What are Cascading Style Sheets (CSS)?
Like your web page, a cascading style sheet consists of ASCII text instructions telling the browser how it can format the document that is being loaded. The CSS instructions can be placed in the web page itself, or it can be placed in a separate document which is linked to the web page. The simplest way to explain a cascading style sheet is to give an example of one. Take the following code, for example, inserted in the HEAD section of a web page.