What is CSS?

Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language.  Basically, CSS is a language that tells your website what it should look like.  You can tell individual letters what color and size to be, or you can apply the style to whole block of content.  You can set a background image or color and change element layouts, also.

Why do we need CSS?

When the Internet and websites were originally imagined, CSS was not part of the vision.  Color, size, and other attributes were simply added directly to the specific elements of the site as it was programmed.  However, this quickly became a nightmare where maintaining large websites.

For example, if you had a website with 50 pages and you wanted all page titles to be blue, then you had to go into the files for all 50 pages and change each individual page title’s color.  With CSS, however, you can create an element class named “page-title”, then simply change the color of that element within the CSS file.  By changing the single line of code within the CSS file, you have updated the page title on all 50 pages at once.