What is CSS?

can some body explain me what is CSS?
give me suggest with honest.

You should try a search on google for CSS, it should give plenty of results/answer.

Basically, CSS (Cascading Style Sheets) is used to style a HTML page.

Unless you actually mean CS:S (Counter-Strik:Source) which is a game.

and you posted in wrong section anyways with css you can put \colour in text in the background also and its similar with html

CSS is an abbreviation for Cascading Style Sheets. Style sheets are simply text files (.css ), composed of lines of code that tell browsers how to display an HTML page. They give the designer more control over the appearance of a webpage by allowing to specifically define styles for elements, such as fonts, on the page. By using CSS one could separate HTML content from its appearance, distinguishing style from structure.