CSS is short for Cascading Style Sheet. Style sheets have actually been around longer than the internet.
We have known style sheets already for so long. They've been around long before the internet had to be invented. Back in the day style sheets were (quite literally) sheets or documents, that excruciatingly detailed stated how all documents for a business must be used.
Style sheet dictates the typefaces that are used in articles, brochures, or press releases, which color is used where, the place of the logo, and lots of other details. Style sheets are to maintain consistency in all documents related to one or more clusters of documents.
Style Sheets in the web sense serve that exact same purpose. CSS is used with the purpose of creating and maintaining consistency across all posts and pages.
This website not only deals with CSS. There are several posts on internet marketing, how to create a great blog, ow to make money from your blog, and so on. I hope you will learn a lot and have some fun reading these articles as well!