What do you mean by CSS?

CSS is a language that describes the style of an HTML document.

Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language.

css is cascading style sheet. it is used for the presentation of the document using markup languages. in this we can set the visual style of the document and user interface is written by HTML, XHTML, and its also applicable to XML and so. IT is very useful in the field of web application as user interface.

In this we have color, font ,background, alignments of texts, images, margins, borders, padding and so.

we can add the css file as external or internal to the HTML

CSS stands for Cascading Style Sheets. CSS describes how HTML elements are to be displayed on screen, paper, or in other media. CSS saves a lot of work. It can control the layout of multiple web pages all at once.

cascading style sheet it is used to  coordinate the page in web site

CSS stands for Cascading style sheets where CSS cares to format and format the pages of the site colors, lines, backgrounds, images and so on aesthetic additions

https://developer.mozilla.org/en-US/docs/Web/CSS