HTML element

An HTML element is a type of HTML (HyperText Markup Language) document component, one of several types of HTML nodes (there are also text nodes, comment nodes and others).^[vague] The first used version of HTML was written by Tim Berners-Lee in 1993 and there have since been many versions of HTML. The current de facto standard is governed by the industry group WHATWG and is known as the HTML Living Standard.

An HTML document is composed of a tree of simple HTML nodes, such as text nodes, and HTML elements, which add semantics and formatting to parts of document (e.g., make text bold, organize it into paragraphs, lists and tables, or embed hyperlinks and images). Each element can have HTML attributes specified. Elements can also have content, including other elements and text.

Concepts[edit]

Elements vs. tags[edit]

As is generally understood, the position of an element is indicated as spanning from a start tag and is terminated by an end tag.^[1] This is the case for many, but not all, elements within an HTML document. The distinction is explicitly emphasised in HTML 4.01 Specification:

Elements are not tags. Some people refer to elements as tags (e.g., "the P tag"). Remember that the element is one thing, and the tag (be it start or end tag) is another. For instance, the HEAD element is always present, even though both start and end HEAD tags may be missing in the markup.^[1]

Similarly the W3C Recommendation HTML 5.1 2nd Edition explicitly says:

Tags are used to delimit the start and end of elements in the markup. (...) The start and end tags of certain normal elements can be omitted, (...)
The contents of the element must be placed between just after the start tag (which might be implied, in certain cases) and just before the end tag (which again, might be implied, in certain cases).
— HTML 5.1 2nd Edition § 8.1.2. Elements § Tags

and:

Certain tags can be omitted.
NOTE:
Omitting an element's start tag (...) does not mean the element is not present; it is implied, but it is still there. For example, an HTML document always has a root <html> element, even if the string <html> doesn't appear anywhere in the markup.
— HTML 5.1 2nd Edition § 8.1.2.4. Optional tags

As HTML (before HTML5) is based on SGML,^[2] its parsing also depends on the Document Type Definition (DTD), specifically an HTML DTD (e.g. HTML 4.01^[3]^{[note 1]}). The DTD specifies which element types are possible (i.e. it defines the set of element types) and also the valid combinations in which they may appear in a document. It is part of general SGML behavior that, where only one valid structure is possible (per the DTD), its explicit statement in any given document is not generally required. As a simple example, the <p> tag indicating the start of a paragraph element should be complemented by a </p> tag indicating its end. But since the DTD states that paragraph elements cannot be nested, an HTML document fragment <p>Para 1 <p>Para 2 <p>Para 3 is thus inferred to be equivalent to <p>Para 1 </p><p>Para 2 </p><p>Para 3. (If one paragraph element cannot contain another, any currently open paragraph must be closed before starting another.) Because this implication is based on the combination of the DTD and the individual document, it is not usually possible to infer elements from document tags alone but only by using an SGML—or HTML—aware parser with knowledge of the DTD. HTML5 creates a similar result by defining what tags can be omitted.^[4]

SGML vs. XML[edit]

SGML is complex, which has limited its widespread understanding and adoption. XML was developed as a simpler alternative. Although both can use the DTD to specify the supported elements and their permitted combinations as document structure, XML parsing is simpler. The relation from tags to elements is always that of parsing the actual tags included in the document, without the implied closures that are part of SGML.^{[note 2]}

HTML as used on the current web is likely to be either treated as XML, by being XHTML, or as HTML5; in either case the parsing of document tags into Document Object Model (DOM) elements is simplified compared to legacy HTML systems. Once the DOM of elements is obtained, behavior at higher levels of interface (example: screen rendering) is identical or nearly so.^{[note 3]}

`%block;` vs. box[edit]

Part of this CSS presentation behavior is the notion of the "box model". This is applied to those elements that CSS considers to be "block" elements, set through the CSS display: block; declaration.

HTML also has a similar concept, although different, and the two are very frequently confused. %block; and %inline; are groups within the HTML DTD that group elements as being either "block-level" or "inline".^[6] This is used to define their nesting behavior: block-level elements cannot be placed into an inline context.^{[note 4]} This behavior cannot be changed; it is fixed in the DTD. Block and inline elements have the appropriate and different CSS behaviors attached to them by default,^[6] including the relevance of the box model for particular element types.

Note though that this CSS behavior can, and frequently is, changed from the default. Lists with <ul><li> ... are %block; elements and are presented as block elements by default. However, it is quite common to set these with CSS to display as an inline list.^[7]

Overview[edit]

Syntax[edit]

\overbrace {\overbrace {{\mathtt {\color {BrickRed}<\!p\ }}\color {Magenta}\underbrace {\mathtt {class}} _{\mathsf {\color {Black}{Attribute \atop name}}}{\mathtt {=''}}\!\underbrace {\mathtt {paragraph}} _{\mathsf {\color {White}{Attr} \atop \color {Black}Attribute\ value}}''{\mathtt {\color {BrickRed}>}}} ^{\mathsf {Start\ tag}}\overbrace {\mathtt {\color {Green}This\ is\ a\ paragraph.}} ^{\mathsf {Content}}\overbrace {\mathtt {\color {BrickRed}<\!/p\!>}} ^{\mathsf {End \atop tag}}} ^{\mathsf {Element}}

Parts of an HTML container element

In the HTML syntax, most elements are written with a start tag and an end tag, with the content in between. An HTML tag is composed of the name of the element, surrounded by angle brackets. An end tag also has a slash after the opening angle bracket, to distinguish it from the start tag. For example, a paragraph, which is represented by the <p> element, would be written as:

<p>In the HTML syntax, most elements are written ...</p>

However, not all of these elements require the end tag, or even the start tag, to be present.^[4] Some elements, the so-called void elements, do not have an end tag. A typical example is the <br> (hard line-break) element. A void element's behavior is predefined, and it cannot contain any content or other elements. For example, an address would be written as:

<p>P. Sherman<br>42 Wallaby Way<br>Sydney</p>

When using XHTML, it is required to open and close all elements, including void elements. This can be done by placing an end tag immediately after the start tag, but this is not legal in HTML 5 and will lead to two elements being created. An alternative way to specify that it is a void element, which is compatible with both XHTML and HTML 5, is to put a / at the end of the tag (not to be confused with the / at the beginning of a closing tag).

<p>P. Sherman<br />42 Wallaby Way<br />Sydney</p>

HTML attributes are specified inside the start tag. For example, the <abbr> element, which represents an abbreviation, expects a title attribute within its opening tag. This would be written as:

<abbr title="abbreviation">abbr.</abbr>

Informally, HTML elements are sometimes referred to as "tags" (an example of synecdoche), though many prefer the term tag strictly in reference to the markup delimiting the start and end of an element.

Element (and attribute) names may be written in any combination of upper or lower case in HTML, but must be in lower case in XHTML.^[8] The canonical form was upper-case until HTML 4, and was used in HTML specifications, but in recent years, lower-case has become more common.

Types of element[edit]

There are three kinds of HTML elements: normal elements, raw text elements, and void elements.

Normal elements usually have both a start tag and an end tag, although for some elements the end tag, or both tags, can be omitted. It is constructed in a similar way:

a start tag (<tag>) marking the beginning of an element, which may incorporate any number of HTML attributes;
some amount of content, including text and other elements;
an end tag, in which the element name is prefixed with a slash: </tag>.

Raw text elements (also known as text or text-only elements) are constructed with:

a start tag (in the form <tag>) marking the beginning of an element, which may incorporate any number of HTML attributes;
some amount of text content, but no elements (all tags, apart from the applicable end tag, will be interpreted as content);
an end tag, in which the element name is prefixed with a slash: </tag>. In some versions of HTML, the end tag is optional for some elements. The end tag is required in XHTML.

An example is the <title> element, which must not contain other elements (including markup of text), only plain text.

Void elements (also sometimes called empty elements, single elements or stand-alone elements) only have a start tag (in the form <tag>), which contains any HTML attributes. They may not contain any children, such as text or other elements. For compatibility with XHTML, the HTML specification^[which?] allows an optional space and slash^{[citation needed]} (<tag /> is permissible). The slash is required in XHTML and other XML applications. Two common void elements are <br /> (for a hard line-break, such as in a poem or an address) and <hr /> (for a thematic break). Other such elements are often place-holders which reference external files, such as the image (<img />) element. The attributes included in the element will then point to the external file in question. Another example of a void element is <link />, for which the syntax is:

<link rel="stylesheet" href="fancy.css" type="text/css">

This <link /> element points the browser at a style sheet to use when presenting the HTML document to the user. In the HTML syntax attributes do not have to be quoted if they are composed only of certain characters: letters, digits, the hyphen-minus and the period. When using the XML syntax (XHTML), on the other hand, all attributes must be quoted, and a spaced trailing slash is required before the last angle bracket:

<link rel="stylesheet" href="fancy.css" type="text/css" />

Attributes[edit]

HTML attributes define desired behavior or indicate additional element properties. Most attributes require a value. In HTML, the value can be left unquoted if it does not include spaces (attribute=value), or it can be quoted with single or double quotes (attribute='value' or attribute="value"). In XML, those quotes are required.

Boolean attributes, on the other hand, do not require a value to be specified. An example is the checked for checkboxes:

<input type=checkbox checked>

In the XML (and thus XHTML) syntax, though, a value is required, and the name should be repeated as the value:

<input type="checkbox" checked="checked" />

Element standards[edit]

HTML elements are defined in a series of freely available open standards issued since 1995, initially by the IETF and subsequently by the W3C.

During the browser wars of the 1990s, developers of user agents (e.g. web browsers) often developed their own elements, some of which have been adopted in later standards. Other user agents may not recognize non-standard elements, and they will be ignored, possibly causing the page to be displayed improperly.

In 1998, XML (a simplified form of SGML) introduced mechanisms to allow anyone to develop their own elements and incorporate them in XHTML documents, for use with XML-aware user agents.^[9]

Subsequently, HTML 4.01 was rewritten in an XML-compatible form, XHTML 1.0 (eXtensible HTML). The elements in each are identical, and in most cases valid XHTML 1.0 documents will be valid or nearly valid HTML 4.01 documents. This article mainly focuses on real HTML, unless noted otherwise; however, it remains applicable to XHTML. See HTML for a discussion of the minor differences between the two.

Element status[edit]

Since the first version of HTML, several elements have become outmoded, and are deprecated in later standards, or do not appear at all, in which case they are invalid (and will be found invalid, and perhaps not displayed, by validating user agents).^[10]

In HTML 4.01 / XHTML 1.0, the status of elements is complicated by the existence of three types of DTD:

Transitional, which contain deprecated elements, but which were intended to provide a transitional period during which authors could update their practices;
Frameset, which are versions of the Transitional DTDs which also allow authors to write frameset documents;
Strict, which is the up-to-date (as at 1999) form of HTML.

HTML5 instead provides a listing of obsolete features to go along with the standardized normative content. They are broken down into "obsolete but conforming" for which implementation instructions exist and "non-conforming" ones that should be replaced.^[11]

The first Standard (HTML 2.0) contained four deprecated elements, one of which was invalid in HTML 3.2. All four are invalid in HTML 4.01 Transitional, which also deprecated a further ten elements. All of these, plus two others, are invalid in HTML 4.01 Strict. While the frame elements are still current in the sense of being present in the Transitional and Frameset DTDs, there are no plans to preserve them in future standards, as their function has been largely replaced, and they are highly problematic for user accessibility.

(Strictly speaking, the most recent XHTML standard, XHTML 1.1 (2001), does not include frames at all; it is approximately equivalent to XHTML 1.0 Strict, but also includes the Ruby markup module.)^[12]

A common source of confusion is the loose use of deprecated to refer to both deprecated and invalid status, and to elements that are expected to be formally deprecated in the future.

Content vs. presentation and behavior[edit]

Since HTML 4, HTML has increasingly focused on the separation of content (the visible text and images) from presentation (like color, font size, and layout).^[13] This is often referred to as a separation of concerns. HTML is used to represent the structure or content of a document, its presentation remains the sole responsibility of CSS style sheets. A default style sheet is suggested as part of the CSS standard, giving a default rendering for HTML.^[14]

Behavior (interactivity) is also kept separate from content, and is handled by scripts. Images are contained in separate graphics files, separate from text, though they can also be considered part of the content of a page.

Separation of concerns allows the document to be presented by different user agents according to their purposes and abilities. For example, a user agent can select an appropriate style sheet to present a document by displaying on a monitor, printing on paper, or to determine speech characteristics in an audio-only user agent. The structural and semantic functions of the markup remain identical in each case.

Historically, user agents did not always support these features. In the 1990s, as a stop-gap, presentational elements (like <b> and <i>) were added to HTML, at the cost of creating problems for interoperability and user accessibility. This is now regarded as outmoded and has been superseded by style sheet-based design; most presentational elements are now deprecated.^[15]

External image files are incorporated with the <img /> or <object /> elements. (With XHTML, the SVG language can also be used to write graphics within the document, though linking to external SVG files is generally simpler.)^[16] Where an image is not purely decorative, HTML allows replacement content with similar semantic value to be provided for non-visual user agents.

An HTML document can also be extended through the use of scripts to provide additional behaviors beyond the abilities of HTML hyperlinks and forms.

The elements <style> and <script>, with related HTML attributes, provide style sheets and scripts.

In the document head, <style /> and <script /> may link to shared external documents, or <style>...</style> and <script>...</script> may contain embedded instructions. (The <link> element can also be used to link style sheets.)
<script /> or <script>...</script> can occur at any point in the document (head or body).
The style attribute is valid in most document body elements (e.g. <div style="...">) for inclusion of inline style instructions.
Event-handling attributes, which provide links to scripts, are optional in most elements.
For user agents which do not operate scripts, the <noscript>...</noscript> element provides embedded alternative content where appropriate; however, it can only be used in the document head and in the body as a block-level element.

Document structure elements[edit]

<html>...</html>: The root element of an HTML document; all other elements are contained in this. The HTML element delimits the beginning and the end of an HTML document.; Both the start and end tags may be omitted (HTML5).^[4]; Standardized in HTML 2.0; still current.
<head>...</head>: (See document head elements for child elements.)
Container for processing information and metadata for an HTML document.; Both the start and end tags may be omitted and inferred from child elements (HTML5).^[4]; Standardized in HTML 5.0; still current.
<body></body>: (See document body elements for child elements.)
Container for the displayable content of an HTML document.; Both the start and end tags may be omitted and inferred from child elements (HTML5).^[4]; Standardized in HTML 2.0; still current.

Document head elements[edit]

<base />

Specifies a base URL for all relative href and other links in the document. Must appear before any element that refers to an external resource. HTML permits only one <base> element for each document. This element has HTML attributes, but no contents.

A development version of this element (as BASE) is mentioned in HTML Tags; standardized in HTML 2.0; still current.

<basefont /> (deprecated)

Specifies a base font size, typeface, and color for the document. Used together with <font> elements. Deprecated in favor of style sheets.

Standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.

<isindex /> (deprecated)

<isindex> could either appear in the document head or in the body, but only once in a document. See Forms.

<link />

Specifies links to other documents, such as previous and next links, or alternate versions.^[17] A common use is to link to external style sheets, using the form, <link rel="stylesheet" type="text/css" href="url" title="description_of_style">.^[18] A less-common, but important, usage is to supply navigation hints consistently through use of microformats. Several common relationships are defined, that may be exposed to users through the browser interface rather than directly in the web page, such as: <link rel="next" href="url">. A document's <head> element may contain any number of <link /> elements. This element has HTML attributes, but no contents.

LINK existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.

<meta />

Can be used to specify additional metadata about a document, such as its author, publication date, expiration date, language, page title, page description, keywords, or other information not provided through the other header elements and HTML attributes. Because of their generic nature, <meta /> elements specify associative key-value pairs. In general, a meta element conveys hidden information about the document. Several meta tags can be used, all of which should be nested in the head element. The specific purpose of each <meta /> element is defined by its attributes. Outside of XHTML, it is often given without the slash (<meta>), despite being a void element.

In one form, <meta /> elements can specify HTTP headers which should be sent by a web server before the actual content. For example, <meta http-equiv="foo" content="bar" /> specifies that the page should be served with an HTTP header called foo that has a value bar.

In the general form, a <meta /> element specifies name and associated content HTML attributes describing aspects of the HTML page. To prevent possible ambiguity, an optional third attribute, scheme, may be supplied to specify a semantic framework that defines the meaning of the key and its value. For example, in <meta name="foo" content="bar" scheme="DC" /> the <meta /> element identifies itself as containing the foo element, with a value of bar, from the DC or Dublin Core resource description framework.

Standardized in HTML 2.0; still current.

<object>...</object>

Used for including generic objects within the document header. Though rarely used within a <head> element, it could potentially be used to extract foreign data and associate it with the current document.

Standardized in HTML 4.0; still current.

<script>...</script>

Can act as a container for script instructions or link to an external script with the optional src attribute.^[19] Also usable in the document body to dynamically generate either both block or inline content.

Standardized in HTML 3.2; still current.

<style>...</style>

Specifies a CSS style for the document, usually in the form, <style type="text/css"> ... </style>. Can either act as a container for style instructions or link to external style sheets – for example, in CSS, with @import directives of the form,^[20] <style> @import url; </style>

Standardized in HTML 3.2; still current.

<title>...</title>

This tag defines a document title. Required in every HTML and XHTML document. User agents may use the title in different ways. For example:

Web browsers usually display it in a window's title bar when the window is open, and (where applicable) in the task bar when the window is minimized.
It may become the default file-name when saving the page.
We can use <title> element only one time in a web page, and when we make another page then we will use again another <title> element with new title (do not take same name for all title tag in website, It can be problem for search engines).
Web search engines' web crawlers may pay particular attention to the words used in the title.

The <title> element must not contain other elements, only text. Only one <title> element is permitted in a document.

Existed in HTML Tags, and was standardized in HTML 2.0; still current.

Document body elements[edit]

In visual browsers, displayable elements can be rendered as either block or inline. While all elements are part of the document sequence, block elements appear within their parent elements:

as rectangular objects which do not break across lines;
with block margins, width, and height properties which can be set independently of the surrounding elements.

Conversely, inline elements are treated as part of the flow of document text; they cannot have margins, width, or height set, and do break across lines.

Block elements[edit]

Block elements, or block-level elements, have a rectangular structure. By default, these elements will span the entire width of its parent element, and will thus not allow any other element to occupy the same horizontal space as it is placed on.

The rectangular structure of a block element is often referred to as the box model, and is made up of several parts. Each element contains the following:

The content of an element is the actual text (or other media) placed between the opening and closing tags of an element.
The padding of an element is the space around the content but which still forms part of the element. Padding should not be used to create white space between two elements. Any background style assigned to the element, such as a background image or color, will be visible within the padding. Increasing the size of an element's padding increases the amount of space this element will take up.
The border of an element is the absolute end of an element and spans the perimeter of that element. The thickness of a border increases the size of an element.
The margin of an element is the white space that surrounds an element. The content, padding, and border of any other element will not be allowed to enter this area unless forced to do so by some advanced CSS placement. Using most standard DTDs, margins on the left and right of different elements will push each other away. Margins on the top or bottom of an element, on the other hand, will not stack or will intermingle. This means that the white space between these elements will be as big as the larger margin between them.

The above section refers only to the detailed implementation of CSS rendering and has no relevance to HTML elements themselves.

Basic text[edit]

<p>...</p>: Creates a paragraph, perhaps the most common block level element.; P existed in HTML Tags, and was standardized in HTML 2.0; still current.
<h1>...</h1>
<h2>...</h2>
<h3>...</h3>
<h4>...</h4>
<h5>...</h5>
<h6>...</h6>: Section headings at different levels. h1 delimits the highest-level heading, h2 the next level down (sub-section), h3 for a level below that, and so on to h6. They are sometimes referred to collectively as hn tags, n meaning any of the available heading levels. Most visual browsers show headings as large bold text by default, though this can be overridden with CSS. Heading elements are not intended merely for creating large or bold text – in fact, they should not be used for explicitly styling text. Rather, they describe the document's structure and organization. Some programs use them to generate outlines and tables of contents.; Headings existed in HTML Tags, and were standardized in HTML 2.0; still current.

Lists[edit]

<dl>...</dl>

A description list (a.k.a. association list or definition list) consists of name–value groups,^[21] and was known as a definition list prior to HTML5.^[22] Description lists are intended for groups of "terms and definitions, metadata topics and values, questions and answers, or any other groups of name–value data".^[23]

DL existed in HTML Tags, and was standardized in HTML 2.0; still current.

<dt>...</dt>

A name in a description list (previously definition term in a definition list).

DT existed in HTML Tags, and was standardized in HTML 2.0; still current.

<dd>...</dd>

A value in a description list (previously definition data in a definition list).

DD existed in HTML Tags, and was standardized in HTML 2.0; still current.

<ol>...</ol>

An ordered (enumerated) list. The type attribute can be used to specify the kind of marker to use in the list, but style sheets give more control. The default is Arabic numbering. In an HTML attribute: <ol type="foo">; or in a CSS declaration: ol { list-style-type: foo; } – replacing foo with one of the following:

A, B, C ... – HTML value: A; CSS value: upper-alpha
a, b, c ... – HTML value: a; CSS value: lower-alpha
I, II, III ... – HTML value: I; CSS value: upper-roman
i, ii, iii ... – HTML value: i; CSS value: lower-roman
1, 2, 3 ... – HTML value: 1; decimal

CSS provides several other options not available as pure-HTML markup, including none, and options for CJK, Hebrew, Georgian, and Armenian script. The attribute is deprecated in HTML 3.2 and 4.01, but not in HTML 5.

OL existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.

<ul>...</ul>

An unordered (bulleted) list. The type of list item marker can be specified in an HTML attribute: <ul type="foo">; or in a CSS declaration: ul { list-style-type: foo; } – replacing foo with one of the following (the same values are used in HTML and CSS): disc (the default), square, or circle. Only the CSS method is supported in HTML5; the attribute is deprecated in HTML 3.2 and 4.01. CSS also provides none, and the ability to replace these bullets with custom images.

UL existed in HTML Tags, and was standardized in HTML 2.0; still current.

<li>...</li>

A list item in ordered (ol) or unordered (ul) lists.

LI existed in HTML Tags, and was standardized in HTML 2.0; still current.

<dir>...</dir> (deprecated)

A directory listing. The original purpose of this element was never widely supported; deprecated in favor of <ul>.

DIR existed in HTML Tags, and was standardized in HTML 2.0; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.

Other block elements[edit]

<address>...</address>: Contact information for the document author.; ADDRESS existed in HTML Tags, and was standardized in HTML 2.0; still current.
<article>...</article>: Main article: Article element
Used for articles and other similar content.; Standardized in HTML5.
<aside>...</aside>: Used for content in a document which is separate from the main page content, for example, sidebars or advertising.; Standardized in HTML5.
<blockquote>...</blockquote>: Main article: Blockquote element

A block level quotation, for when the quotation includes block level elements, e.g. paragraphs. The cite attribute (not to be confused with the <cite> element) may give the source, and must be a fully qualified Uniform Resource Identifier.
The default presentation of block quotations in visual browsers is usually to indent them from both margins. This has led to the element being unnecessarily used just to indent paragraphs, regardless of semantics. For quotations not containing block level elements see the quote (<q>) element.; BLOCKQUOTE existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current. See blockquote element for more information.
<center>...</center> (deprecated): Creates a block-level center-aligned division. Deprecated in favor of <div> or another element with centering defined using style sheets.; Standardized in HTML 3.2; deprecated in HTML 4.0; not supported in HTML5.
<del>...</del>: Marks a deleted section of content. This element can also be used as inline.; Standardized in HTML 4.0; still current.
<div>...</div>: Main article: Span and div
A block-level logical division. A generic element with no semantic meaning used to distinguish a document section, usually for purposes such as presentation or behavior controlled by style sheets or DOM calls.; Proposed in the HTML 3.0 Drafts; Standardized in HTML 3.2; still current.
<figure>...</figure>: Used to group images and captions, along with <figcaption>.; Standardized in HTML5.
<figcaption>...</figcaption>: A caption for an image. Always placed inside the <figure> element.; Standardized in HTML5.
<footer>...</footer>: Used for document footers. These might contain author or copyright information, or links to other pages.; Standardized in HTML5.
<header>...</header>: Used for document headers. These typically contain content introducing the page.; Standardized in HTML5.
<hr />: A thematic break (originally: horizontal rule). Presentational rules can be drawn with style sheets.; Standardized in HTML 2.0; still current.
<ins>...</ins>: Marks a section of inserted content. This element can also be used as inline.; Standardized in HTML 4.0; still current.
<main>...</main>: Contains the main content of a document.; Standardized in HTML 5.1.
<menu>...</menu>: HTML 2.0: A menu listing. Should be more compact than a <ul> list.; MENU existed in HTML Tags, and was standardized in HTML 2.0; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict; then redefined in HTML5, removed in HTML 5.2, but is included in the HTML Living Standard in 2019.
<nav>...</nav>: Used in navigational sections of articles (areas of webpages which contain links to other webpages).; Standardized in HTML5.
<noscript>...</noscript>: Replacement content for scripts. Unlike script this can only be used as a block-level element.; Standardized in HTML 4.0; still current.
<pre>...</pre>: Pre-formatted text. Text within this element is typically displayed in a non-proportional font exactly as it is laid out in the file (see ASCII art). Whereas browsers ignore white-space for other HTML elements, in <pre>...</pre>, white-space should be rendered as authored. (With the CSS properties: { white-space: pre; font-family: monospace; }, other elements can be presented in the same way.) This element can contain any inline element except: <image>, <object>, <big>, <small>, <sup>, and <sub>...</sub>.; PRE existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<section>...</section>: Used for generic sections of a document. This is different from <div> in that it is only used to contain sections of a page, which the W3C defines as a group of content with a similar theme.; Standardized in HTML5.
<script>...</script>: Places a script in the document. Also usable in the head and in inline contexts. It may be used as <script /> with a src attribute to supply a URL from which to load the script, or used as <script>...</script> around embedded script content. Note: <script> is not itself either a block or inline element; by itself it should not display at all, but it can contain instructions to dynamically generate either both block or inline content.; Standardized in HTML 3.2; still current.

Inline elements[edit]

Inline elements cannot be placed directly inside the <body> element; they must be wholly nested within block-level elements.^[24]

Anchor[edit]

<a>...</a>

An anchor element is called an anchor because web designers can use it to "anchor" a URL to some text on a web page. When users view the web page in a browser, they can click the text to activate the link and visit the page whose URL is in the link.^[25]

In HTML, an anchor can be either the origin (the anchor text) or the target (destination) end of a hyperlink.

With the attribute href,^[26] the anchor becomes a hyperlink to either another part of the document or another resource (e.g. a webpage) using an external URL. Alternatively (and sometimes concurrently), with the name or id HTML attributes set, the element becomes a link target. A Uniform Resource Locator (URL) can link to this target via a fragment identifier. In HTML5, any element can now be made into a target by using the id attribute,^[27] so using <a name="foo">...</a> is not necessary, although this way of adding anchors continues to work.

To illustrate: the header of a table of contents section on example.com's homepage could be turned into a target by writing: <h2><a name="contents">Table of contents</a></h2>.

Continuing with this example, now that the section has been marked up as a target, it can be referred to from external sites with a link like: <a href="http://example.com#contents">see contents</a>;

or with a link on the same page like: <a href="#contents">contents, above</a>.

The attribute title may be set to give brief information about the link: <a href="URL" title="additional information">link text</a>.

In most graphical browsers, when the cursor hovers over a link, the cursor changes into a hand with an extended index finger and the title value is displayed in a tooltip or in some other manner. Some browsers render alt text the same way, although this is not what the specification calls for.

A existed in HTML Tags, and was standardized in HTML 2.0;

Phrase elements[edit]

Phrase elements are used for marking up phrases and adding structure or semantic meaning to text fragments. For example, the <em> and <strong> tags can be used for adding emphasis to text.

General[edit]

<abbr>...</abbr>: Marks an abbreviation, and can make the full form available: <abbr title="abbreviation">abbr.</abbr>; Standardized in HTML 4.0; still current.
<acronym>...</acronym> (deprecated): Similar to the <abbr> element, but marks an acronym: <acronym title="Hyper-Text Mark-up Language">HTML</acronym>; Standardized in HTML 4.0; still current, not supported in HTML5. Recommended replacement is the abbr tag.^[28]
<dfn>...</dfn>: Inline definition of a single term.; DFN existed in HTML Internet Draft 1.2, and was fully standardized in HTML 3.2; still current.
<em>...</em>: Emphasis (conventionally displayed in italics); EM existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<strong>...</strong>: importance; originally strong emphasis (conventionally displayed bold). An aural user agent may use different voices for emphasis.; STRONG existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current, redefined in HTML5.

Computer phrase elements[edit]

These elements are useful primarily for documenting computer code development and user interaction through differentiation of source code (<code>), variables (<var>), user input (<kbd>), and terminal or other output (<samp>).

<code>...</code>: A code snippet (code example). Conventionally rendered in a mono-space font.; CODE existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<kbd>...</kbd>: Keyboard – text to be entered by the user (kbd example).; KBD existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<samp>...</samp>: Sample output – from a program or script: (samp example).; SAMP existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.
<var>...</var>: Variable (var example).; VAR existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.

Presentation[edit]

As visual presentational markup only applies directly to visual browsers, its use is discouraged. Style sheets should be used instead. Several of these elements are deprecated or invalid in HTML 4 / XHTML 1.0, and the remainder are invalid in the current draft of XHTML 2.0. The current draft of HTML5, however, re-includes <s>, <u>, and <small>, assigning new semantic meaning to each. In an HTML5 document, the use of these elements is no longer discouraged, provided that it is semantically correct.

<b>...</b>

In HTML 4, set font to boldface where possible. Equivalent CSS: { font-weight: bold; }. The <strong> element usually has the same effect in visual browsers, as well as having more semantic meaning, under HTML 4.01. In HTML5, however, <b> has its own meaning, distinct from that of <strong>. It denotes "text to which attention is being drawn for utilitarian purposes without conveying any extra importance and with no implication of an alternate voice or mood."^[29]

B existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current, redefined in HTML5.

<i>...</i>

In HTML 4, set font to italic where possible. Equivalent CSS: { font-style: italic; }. Using <em>...</em> has the same visual effect in most browsers, as well as having a semantic meaning as emphasis, under HTML 4.01. (Purely typographic italics have many non-emphasis purposes, as HTML 5 more explicitly recognized.) In HTML5, however, <i> has its own semantic meaning, distinct from that of <em>. It denotes "a different quality of text" or "an alternate voice or mood" e.g., a thought, a ship name, a binary species name, a foreign-language phrase, etc.^[30]

I existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current, redefined in HTML5.

<u>...</u>

In HTML 4, underlined text. Equivalent CSS: { text-decoration: underline; }. Deprecated in HTML 4.01. Restored in HTML5. In HTML5, the <u> element denotes "a span of text with an unarticulated, though explicitly rendered, non-textual annotation, such as labelling the text as being a proper name in Chinese text (a Chinese proper name mark), or labelling the text as being misspelt." The HTML5 specification reminds developers that other elements are almost always more appropriate than <u> and admonishes designers not to use underlined text where it could be confused for a hyper-link.^[31]

U existed in HTML Internet Draft 1.2, was standardized in HTML 3.2 but was deprecated in HTML 4.0 Transitional and was invalid in HTML 4.0 Strict. Reintroduced in HTML5.

<small>...</small>

In HTML 4, decreased font size (smaller text). Equivalent CSS: { font-size: smaller; } In HTML5, the <small> element denotes "side comments such as small print."^[32] This has caused some confusion with the <aside>...</aside> element.

Standardized in HTML 3.2; still current.

<s>...</s>

In HTML 4, indicated strike-through text (~~Strikethrough~~) and was equivalent to <strike>. In HTML5, the <s> element denotes information that is "no longer accurate or no longer relevant", and is not to be confused with <del>, which indicates removal/deletion.^[33]

S was deprecated in HTML 4.0 Transitional (having not appeared in any previous standard), and was invalid in HTML 4.0 Strict. Reintroduced in HTML5, which instead deprecated <strike>.

<big>...</big> (deprecated)

Increased font size (bigger text). Equivalent CSS: { font-size: larger; }

Standardized in HTML 3.2; not supported in HTML5.

<strike>...</strike> (deprecated)

Strike-through text (~~Strikethrough~~), (Equivalent CSS: { text-decoration: line-through; })

STRIKE was standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict.

<tt>...</tt> (deprecated)

Fixed-width font (typewriter-like), also known as teletype, thus "tt". (Equivalent CSS: { font-family: monospace; })

TT existed in HTML Internet Draft 1.2, and was Standardized in HTML 2.0; not supported^[34] in HTML5. Possible replacements: <kbd> for marking user input, <var> for variables (usually rendered italic, and not with a change to monospace), <code> for source code, <samp> for output.^[34]

<font>...</font> (deprecated)

<font [color=<var>color</var>] [size=<var>size</var>] [face=<var>face</var>]>...</font> Can specify the font color with the color attribute (note the American spelling), typeface with the face attribute, and absolute or relative size with the size attribute. Examples (all uses are deprecated, use CSS equivalents if possible):

<font color="green">text</font> creates green text.
<font color="#114499">text</font> creates text with hexadecimal color #114499.
<font size="4">text</font> creates text with size 4. Sizes are from 1 to 7. The standard size is 3, unless otherwise specified in the <body> or other tags.
<font size="+1">text</font> creates text with size 1 bigger than the standard. <font size="-1">text</font> is opposite.
<font face="Courier">text</font> makes text with Courier font.

Equivalent CSS for font attributes:

<font size="N"> corresponds to {font-size: Yunits} (the HTML specification does not define the relationship between size N and unit-size Y, nor does it define a unit).
<font color="red"> corresponds to { color: red; }
<font face="Times New Roman"> corresponds to { font-family: 'Times New Roman', Times, serif; } – CSS supports a font stack, of two or more alternative fonts.

Standardized in HTML 3.2; deprecated in HTML 4.0 Transitional; invalid in HTML 4.0 Strict. Not part of HTML5.

Span[edit]

<span>...</span>: Main article: Span and div
An inline logical division. A generic element with no semantic meaning used to distinguish a document section, usually for purposes such as presentation or behavior controlled by style sheets or DOM calls.; Standardized in HTML 4.0; still current.

Other inline elements[edit]

<br />: A forced line break.; Standardized in HTML 2.0; still current.
<bdi>...</bdi>: Isolates an inline section of text that may be formatted in a different direction from other text outside of it, such as user-generated content with unknown directionality.; Standardized in HTML5.
<bdo>...</bdo>: Marks an inline section of text in which the reading direction is the opposite from that of the parent element.; Standardized in HTML 4.0; still current.
<cite>...</cite>: A citation or a reference for a quote or statement in the document.; CITE existed in HTML Internet Draft 1.2, and was standardized in HTML 2.0; still current.; Note: The HTML 5 specifications have been confusingly forked,^[35] including with regard to this element. In HTML 4 and earlier, <cite> was for "a citation or a reference to other sources" without any particular limitations or requirements.^[36] The W3C HTML 5 spec uses a refinement of this idea, reflecting how the element has historically been used, but now requiring that it contain (but not be limited to) at least one of "the title of the work or the name of the author (person, people or organization) or an URL reference, or a reference in abbreviated form as per the conventions used for the addition of citation metadata."^[37] But the WHATWG spec only permits the element to be used around the title of a work.^[38] The W3C specs began with the broader definition, then switched to the very narrow one after WHATWG made this change. However, W3C reverted their own change in 2012, in response to negative developer-community feedback; the element was in broadly-deployed use with the broader scope, e.g., various blog and forum platforms wrap commenters' IDs and e-mail addresses in <cite>...</cite>, and people using the element for bibliographic citations were (and still are) routinely wrapping each entire citation in this element. Another problem with the element is that WHATWG recommends that it be italicized by default (thus almost all browsers do so), because it (in their view) is only for publication titles. By convention, however, only certain kinds of titles actually take italics, while others are expected to be put in quotation marks, and standards may actually vary by publishing context and language. Consequently, many website authors and admins use a site-wide stylesheet to undo this element's auto-italics.
<data>...</data>: Links inline content with a machine-readable translation.; Standardized in HTML5.^[39]
<del>...</del>: Deleted text. Typically rendered as a strikethrough: ~~Deleted text.~~; Standardized in HTML 4.0; still current.
<ins>...</ins>: Inserted text. Often used to mark up replacement text for material struck with <del> or <s>. Typically rendered underlined:

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Concepts[edit]

Elements vs. tags[edit]

SGML vs. XML[edit]

%block; vs. box[edit]

Overview[edit]

Syntax[edit]

Types of element[edit]

Attributes[edit]

Element standards[edit]

Element status[edit]

Content vs. presentation and behavior[edit]

Document structure elements[edit]

Document head elements[edit]

Document body elements[edit]

Block elements[edit]

Basic text[edit]

Lists[edit]

Other block elements[edit]

Inline elements[edit]

Anchor[edit]

Phrase elements[edit]

General[edit]

Computer phrase elements[edit]

Presentation[edit]

Span[edit]

Other inline elements[edit]

`%block;` vs. box[edit]