What does CSS stand for?

CSS stands for Cascading Style Sheets. It is the language used to control how documents such as HTML pages are presented, including their colors, fonts, spacing, layout, and responsive behavior.

The word “cascading” describes the priority system used when several style rules apply to the same element. Browser defaults, author styles, user preferences, selector specificity, inheritance, and rule order can all affect which declaration wins. This makes CSS predictable while allowing different sources of styling to work together.

CSS was first proposed by Håkon Wium Lie in 1994 while he was working with Tim Berners-Lee. Bert Bos became an important collaborator, and the first official CSS specification, CSS1, became a W3C Recommendation in December 1996.

CSS is commonly confused with HTML. HTML describes a page’s structure and content; CSS describes its presentation. JavaScript is a third major Web technology, generally used for behavior and interactivity. Keeping styling in reusable CSS files also lets many pages share one visual system and lets browsers cache those files.