Cascading Style Sheet Xtensible Markup Language

CSS

• CSS is an acronym for Cascading Style Sheets.
• CSS is a style language that defines layout of HTML documents
• CSS covers fonts, colours, margins, lines, height, width, background images, advanced position.
• HTML can be (mis-)used to add layout to websites.
• But CSS offers more options and is more accurate and sophisticated.
• CSS is supported by all browsers today.

CSS and HTML 

1. HTML is used to structure content.
2. CSS is used for formatting structured content.
3. Many new layout tags such as were only supported by one type of browser. 
4. "You need browser X to view this page" became a common disclaimer on web sites. 
5. CSS was invented to remedy this situation by providing web designers with sophisticated layout opportunities separation of the presentation style of documents from the content of documents, makes site maintenance a lot easier. ported by all browsers.

XML

• XML was designed to transport and store data.
• HTML was designed to display data.
• XML is not a replacement for HTML.
• XML Does not DO Anything 
• The note above is quite self descriptive. It has sender and receiver information, it also has a heading and a message body.
• But still, this XML document does not DO anything.
• It is just pure information wrapped in tags. Someone must write a piece of software to send, receive or display it.
• The tags in the example above (like and ) are not defined in any XML standard. These tags are "invented" by the author of the XML document. 
• That is because the XML language has no predefined tags. 
• The tags used in HTML (and the structure of HTML) are predefined. HTML documents can only use tags defined in the HTML standard (like , <h1>, etc.). 
• XML allows the author to define his own tags and his own document structure. 
• XML is a software- and hardware-independent tool for carrying information.