The background-position CSS property sets the initial position for each background image. The position is relative to the position layer set by background-origin.
The background-repeat CSS property sets how background images are repeated. A background image can be repeated along the horizontal and vertical axes, or not repeated at all.
The background-size CSS property sets the size of the element's background image. The image can be left to its natural size, stretched, or constrained to fit the available space.
Indicates whether input elements can by default have their values automatically completed by the browser. autocomplete attributes on form elements override it on <form>.
Indicates if the fetching of the media must be done using a CORS request. Media data from a CORS request can be reused in the <canvas> element without being marked "tainted". If the crossorigin attribute is not specified, then a non-CORS request is sent (without the Origin request header), and the browser marks the media as tainted and restricts access to its data, preventing its usage in <canvas> elements. If the crossorigin attribute is specified, then a CORS request is sent (with the Origin request header); but if the server does not opt into allowing cross-origin access to the media data by the origin site (by not sending any Access-Control-Allow-Origin response header, or by not including the site's origin in any Access-Control-Allow-Origin response header it does send), then the browser blocks the media from loading, and logs a CORS error to the devtools console.
The display CSS property sets whether an element is treated as a block or inline element and the layout used for its children, such as flow layout, grid or flex.
Intended to provide a hint to the browser about what the author thinks will lead to the best user experience when loading a media object.
The default value is different for each browser. The spec advises it to be set to Preload.metadata.
Used to annotate an instance or static method m. Indicates that m must
either be abstract or must return a newly allocated object or null. In
addition, every method that either implements or overrides m is implicitly
annotated with this same annotation.
Used to annotate an instance member (method, getter, setter, operator, or
field) m. Indicates that every invocation of a member that overrides m
must also invoke m. In addition, every method that overrides m is
implicitly annotated with this same annotation.
Used to annotate an instance member (method, getter, setter, operator, or
field) m in a class C or mixin M. Indicates that m should not be
overridden in any classes that extend or mixin C or M.
Used to annotate a class, mixin, extension, function, method, or typedef
declaration C. Indicates that any type arguments declared on C are to
be treated as optional.
Used to annotate an instance member in a class or mixin which is meant to
be visible only within the declaring library, and to other instance members
of the class or mixin, and their subtypes.
Used to annotate a named parameter p in a method or function f.
Indicates that every invocation of f must include an argument
corresponding to p, despite the fact that p would otherwise be an
optional parameter.
The <a> HTML element (or anchor element), with its href attribute, creates a hyperlink to web pages, files, email addresses, locations in the same page, or anything else a URL can address.
The <article> HTML element represents a self-contained composition in a document, page, application, or site, which is intended to be independently distributable or reusable (e.g., in syndication). Examples include: a forum post, a magazine or newspaper article, or a blog entry, a product card, a user-submitted comment, an interactive widget or gadget, or any other independent item of content.
The <aside> HTML element represents a portion of a document whose content is only indirectly related to the document's main content. Asides are frequently presented as sidebars or call-out boxes.
The <audio> HTML element is used to embed sound content in documents. It may contain one or more audio sources, represented using the src attribute or the <source> element: the browser will choose the most suitable one. It can also be the destination for streamed media, using a MediaStream.
The <b> HTML element is used to draw the reader's attention to the element's contents, which are not otherwise granted special importance. This was formerly known as the Boldface element, and most browsers still draw the text in boldface. However, you should not use <b> for styling text; instead, you should use the CSS font-weight property to create boldface text, or the <strong> element to indicate that text is of special importance.
The <blockquote> HTML element indicates that the enclosed text is an extended quotation. Usually, this is rendered visually by indentation. A URL for the source of the quotation may be given using the cite attribute, while a text representation of the source can be given using the <cite> element.
The <br> HTML element produces a line break in text (carriage-return). It is useful for writing a poem or an address, where the division of lines is significant.
The <button> HTML element is an interactive element activated by a user with a mouse, keyboard, finger, voice command, or other assistive technology. Once activated, it then performs a programmable action, such as submitting a form or opening a dialog.
The <code> HTML element displays its contents styled in a fashion intended to indicate that the text is a short fragment of computer code. By default, the content text is displayed using the user agent's default monospace font.
The <datalist> HTML element contains a set of <option> elements that represent the permissible or recommended options available to choose from within other controls.
The <details> HTML element creates a disclosure widget in which information is visible only when the widget is toggled into an "open" state. A summary or label must be provided using the <summary> element.
The <div> HTML element is the generic container for flow content. It has no effect on the content or layout until styled in some way using CSS (e.g. styling is directly applied to it, or some kind of layout model like Flexbox is applied to its parent element).
The <em> HTML element marks text that has stress emphasis. The <em> element can be nested, with each level of nesting indicating a greater degree of emphasis.
The <embed> HTML element embeds external content at the specified point in the document. This content is provided by an external application or other source of interactive content such as a browser plug-in.
The <footer> HTML element represents a footer for its nearest ancestor sectioning content or sectioning root element. A <footer> typically contains information about the author of the section, copyright data or links to related documents.
The <header> HTML element represents introductory content, typically a group of introductory or navigational aids. It may contain some heading elements but also a logo, a search form, an author name, and other elements.
The <hr> HTML element represents a thematic break between paragraph-level elements: for example, a change of scene in a story, or a shift of topic within a section.
The <html> HTML element represents the root (top-level element) of an HTML document, so it is also referred to as the root element. All other elements must be descendants of this element.
The <i> HTML element represents a range of text that is set off from the normal text for some reason, such as idiomatic text, technical terms, taxonomical designations, among others. Historically, these have been presented using italicized type, which is the original source of the <i> naming of this element.
The <input> HTML element is used to create interactive controls for web-based forms in order to accept data from the user; a wide variety of types of input data and control widgets are available, depending on the device and user agent. The <input> element is one of the most powerful and complex in all of HTML due to the sheer number of combinations of input types and attributes.
The <li> HTML element is used to represent an item in a list. It must be contained in a parent element: an ordered list (<ol>), an unordered list (<ul>), or a menu (<menu>). In menus and unordered lists, list items are usually displayed using bullet points. In ordered lists, they are usually displayed with an ascending counter on the left, such as a number or letter.
The <link> HTML element specifies relationships between the current document and an external resource. This element is most commonly used to link to stylesheets, but is also used to establish site icons (both "favicon" style icons and icons for the home screen and apps on mobile devices) among other things.
The <main> HTML element represents the primary content of a document, distinct from content that is repeated across multiple pages such as site headers, footers, and navigation bars.
The <nav> HTML element represents a section of a page whose purpose is to provide navigation links, either within the current document or to other documents. Common examples of navigation sections are menus, tables of contents, and indexes.
The <object> HTML element represents an external resource, which can be treated as an image, a nested browsing context, or a resource to be handled by a plugin.
The <option> HTML element is used to define an item contained in a <select>, an <optgroup>, or a <datalist> element. As such, <option> can represent menu items in popups and other lists of items in an HTML document.
The <p> HTML element represents a paragraph. Paragraphs are usually represented in visual media as blocks of text separated from adjacent blocks by blank lines and/or first-line indentation, but HTML paragraphs can be any structural grouping of related content, such as images or form fields.
The <polyline> SVG element is an SVG basic shape that creates straight lines connecting several points. Typically a polyline is used to create open shapes as the last point doesn't have to be connected to the first point.
The <pre> HTML element represents preformatted text which is to be presented exactly as written in the HTML file. The text is typically rendered using a non-proportional, or monospaced, font. Whitespace inside this element is displayed as written.
The <rect> element is a basic SVG shape that draws rectangles, defined by their position, width, and height. The rectangles may have their corners rounded.
The <s> HTML element renders text with a strikethrough, or a line through it. Use the <s> element to represent things that are no longer relevant or no longer accurate. However, <s> is not appropriate when indicating document edits; for that, use the <del> and <ins> elements, as appropriate.
The <script> HTML element is used to embed executable code or data; this is typically used to embed or refer to JavaScript code. The <script> element can also be used with other languages, such as WebGL's GLSL shader programming language and JSON.
The <section> HTML element represents a generic standalone section of a document, which doesn't have a more specific semantic element to represent it. Sections should always have a heading, with very few exceptions.
The <small> HTML element represents side-comments and small print, like copyright and legal text, independent of its styled presentation. By default, it renders text within it one font-size smaller, such as from small to x-small.
The <source> HTML element specifies multiple media resources for the <picture>, the <audio> element, or the <video> element. It is an empty element, meaning that it has no content and does not have a closing tag. It is commonly used to offer the same media content in multiple file formats in order to provide compatibility with a broad range of browsers given their differing support for image file formats and media file formats.
The <span> HTML element is a generic inline container for phrasing content, which does not inherently represent anything. It can be used to group elements for styling purposes (using the class or id attributes), or because they share attribute values, such as lang. It should be used only when no other semantic element is appropriate. <span> is very much like a <div> element, but <div> is a block-level element whereas a <span> is an inline element.
The <strong> HTML element indicates that its contents have strong importance, seriousness, or urgency. Browsers typically render the contents in bold type.
The <summary> HTML element specifies a summary, caption, or legend for a <details> element's disclosure box. Clicking the <summary> element toggles the state of the parent <details> element open and closed.
The <svg> element is a container that defines a new coordinate system and viewport. It is used as the outermost element of SVG documents, but it can also be used to embed an SVG fragment inside an SVG or HTML document.
The <textarea> HTML element represents a multi-line plain-text editing control, useful when you want to allow users to enter a sizeable amount of free-form text, for example a comment on a review or feedback form.
The <u> HTML element represents a span of inline text which should be rendered in a way that indicates that it has a non-textual annotation. This is rendered by default as a simple solid underline, but may be altered using CSS.
The <video> HTML element embeds a media player which supports video playback into the document. You can use <video> for audio content as well, but the <audio> element may provide a more appropriate user experience.
