The CSS Beginner Tutorial assumes that you know as much about CSS as you do about the cumulative effects of sea squirt discharge on the brain chemistry of Germanic ammonites. The purpose of this guide is to teach the bare essentials - just enough to get started. The CSS Intermediate Tutorial and CSS Advanced Tutorial go into more depth about CSS.
CSS, or Cascading Styles Sheets, is a way to style and present HTML. Whereas the HTML is the meaning or content, the style sheet is the presentation of that document.
Styles don’t smell or taste anything like HTML, they have a format of ‘property: value’ and most properties can be applied to most HTML tags.