CSS is the language we use to style an HTML document.
CSS describes how HTML elements should be displayed.
What is CSS?
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
External stylesheets are stored in CSS files
Why Use CSS?
CSS is used to define styles for your web pages, including the design, layout and variations in display for different devices and screen sizes.