HTML

The HyperText Markup language or HTML is the indications markup language for documents intentional to be displayed in a web browser. It can be assisted by technologies such as Cascading category Sheets CSS together with scripting languages such as JavaScript.

Web browsers get HTML documents from a web server or from local storage & render the documents into multimedia web pages. HTML describes the cut of a web page semantically and originally quoted cues for the format of the document.

images and other objects such as angle brackets. Tags such as <img /> and <input /> directly introduce content into the page. Other tags such as <p> surround and give information approximately a object that is caused or produced by something else or done as a reaction to a question document text and may include other tags as sub-elements. Browsers make not display the HTML tags but use them to interpret the content of the page.

HTML can embed entry written in a HTML5, is used to display video and audio, primarily using the <canvas> element, in collaboration with javascript.

Semantic HTML

Semantic HTML is a way of writing HTML that emphasizes the meaning of the encoded information over its delivered look. HTML has mentioned semantic markup from its inception, but has also included presentational markup, such as <font>, <i> and <center> tags. There are also the semantically neutral span and div tags. Since the behind 1990s, when Cascading Style Sheets were beginning to make-up in nearly browsers, web authors have been encouraged to avoid the usage of presentational HTML markup with a idea to the separation of presentation and content.

In a 2001 discussion of the Semantic Web, Tim Berners-Lee and others gave examples of ways in which intelligent software "agents" may one day automatically crawl the web and find, filter and correlate ago unrelated, published facts for the good of human users. Such agents are non commonplace even now, but some of the ideas of Web 2.0, mashups and price comparison websites may be coming close. The main difference between these web a formal request to be considered for a position or to be allowed to do or have something. hybrids and Berners-Lee's semantic agents lies in the fact that the current aggregation and hybridization of information is usually designed in by web developers, who already know the web locations and the API semantics of the specific data they wish to mash, compare and combine.

An important type of web agent that does crawl and read web pages automatically, without prior knowledge of what it might find, is the web crawler or search-engine spider. These software agents are dependent on the semantic clarity of web pages they find as they use various techniques and algorithms to read and index millions of web pages a day and manage web users with search facilities without which the World Wide Web's value would be greatly reduced.

In order for search-engine spiders to be experienced to rate the significance of pieces of text they find in HTML documents, and also for those devloping mashups and other hybrids as well as for more automated agents as they are developed, the semantic tables that make up in HTML need to be widely and uniformly applied to bring out the meaning of published text.

Presentational markup tags are deprecated in current HTML and XHTML recommendations. The majority of presentational attaches from previous versions of HTML are no longer authorises as they lead to poorer accessibility, higher cost of site maintenance, and larger document sizes.

Good semantic HTML also improves the accessibility of web documents see also Web Content Accessibility Guidelines. For example, when a screen reader or audio browser can correctly ascertain the structure of a document, it will not damage the visually impaired user's time by reading out repeated or irrelevant information when it has been marked up correctly.