CSS was developed to separate content and presentation in the markup language HTML, and to make layout properties like character and paragraph formats for a website accessible from a centralized location. This allows for centralized format changes without the need to modify individual elements in various documents.
It is possible to define what are called classes in CSS, describing how content should appear. You can specify attributes like fonts, font sizes, line heights, margins, various colors, borders, and more. This greatly simplifies the process of programming website layouts.