CSS (Cascading Style Sheets) is a style sheet language used for describing the presentation of a document written in a markup language. A style sheet is a collection of rules that tells a web browser how to display a document written in HTML or XML.
CSS is used to style all HTML tags, including the document’s body, headings, paragraphs, and other pieces of text. CSS can also be used to style the display of table elements, grid elements, and images.
CSS is often used to create responsive designs that adapt to the size of the user’s device screen. Responsive designs can be created by using media queries to target different screen sizes and devices.
CSS is also used to create animations and transformations, and to manage the layout of elements on a webpage.
CSS is managed by a group called the CSS Working Group (CSSWG). The CSSWG actively develops and maintains official recommendations called “The CSS Grid Layout Module Level 1” and “Vendor-Specific Extensions to CSS”.