HTML means HyperText Markup Language. This is used by web browsers to display pages visually. HTML is based on the idea of tags, enclosed in the '<' and '>' characters. For eg: <p>example paragraph</p>.
Usually, all the HTML tags come in pairs - for eg, <i> and </i>.
The first tag is the opening tag, while the second, the end tag. Inside these tags, web developers can add images, text, flash objects or other such informations. Also, web browsers can use the informations for CSS files to show informations and modify the structure of the page.
The W3C organization maintains HTML and CSS development and encourages using CSS over HTML presentational tags. HTMLs first aparition was in a document called HTML Tags in 1991, mentioned by Tim Berners-Lee. He describes 20 elements from the simple structure of the HTML from then. Besides the anchor link, these 20 elements are very influenced by the SMGLguid language, a SGML documentation used at CERN (European Center for Nuclear Research).
HTML is currently at version 4.01, a new version, HTML5 being in development.
XHTML means eXtensible HyperText Markup Language and is a part of a big family of XML languages, created to extend HTML. While HTML was built as a SGML application, XHTML was created as a extension for XML. There are a number of differences between HTML and XHTML, a few being:
- XHTML needs all the elemets to be closed, either by a separate tag, or by a self-closing tag (for eg: <link />), while HTML syntax alows tags to not be closed (for eg, <br>) or can be determined automatically when to be closed
- XHTML is case sensitive, meaning that a tag will need to be closed with the same format.
- HTML is case insensitive.
To be continued.
Cosmin | Pixelfind
