How often we couldn't understand when an article explains CSS because of its terminology? Words like "element", "class", "selector" and so on, can get mixed up in our brain, and we feel like we are missing something.
Don't worry, because here I explain it all, and so there won't be any confusion anymore.
CSS stylesheetsCSS stands for Cascading Style Sheet.
I believe you already know how a stylesheet is built. Anyway, it is important to remember that a stylesheet is a set of CSS rules. It could be external (we link to the stylesheet in the head of the page), it could be embedded directly in the head of a document or it could be inline (inside the HTML element we want to style).
When we link to an external stylesheet we use the following syntax:
<link rel="stylesheet" type="text/css" href="stylesheetfilename.css" />