CSS stands for Cascading Style Sheets. CSS based web pages have many benefits. They may be faster to download, more uniform, and much much easier to modify at a future date.

Most web sites have a "skin" or the design template that helps every page on the site look uniform and consistent. There are multiple ways to manage that skin. Some web masters choose the tedious, laborious method of formatting every single page individually. If  changes are to be made to the site's look, every single page will have to be uniformly changed. Some designers will use "include files" to keep structure uniform. Some will use a database and call the content into a template when a link is clicked. This works well if you know how to program in php, asp, ruby, .net, etc. and know how to use a data base. Most savvy designers implement some form of CSS file.

A global CSS (or multiple of them) contains all of the properties of the different elements within the site. In layman's terms, the colors, fonts, sizes, backgrounds, etc. all sit in one file. Then, each web page looks at that file when it downloads to see how it should color its title and content. It knows how big to make the font. It can resize a table or image. In short, the styles to format the page are all in one place.

Resources:

• Template CMS tools using CSS
• CSS styles
• CSS Introduction
• Cascading Style Sheets