CSS, known as the Cascading Style Sheets, is a programming language used to define the style of a website.
Information:
CSS includes information about fonts, spacing, colors, graphics, and layouts along with how each should be applied to a particular website. CSS defines how HTML elements should appear on a screen. In other words, Javascript is the behavior, CSS is the style, and HTML is the structure. CSS can be divided into three different types as follows:
Inline CSS - this type of style is specified by the style attribute on an HTML tag.
Internal or Embedded CSS - it is useful for styling a single HTML document uniquely.
External CSS - the external CSS file contains only style properties via tag attributes. It should be a separate .css file, with a link tag for connecting to the HTML document.