Understanding SQL Server Licensing
May 5, 2005[From Developer.com]
Sometimes, buying software is simple. If you want a copy of a simple HTML editor, for example, you just go to the vendor's Web site, find out how much it costs, fill out the online order form with your credit card number, and download your copy. But as you start dealing with more complex programs this simple model breaks down. By the time you get to an enterprise application such as Microsoft SQL Server, the story is immensely complicated. But if you're responsible for buying SQL Server, it's important to understand the various options involved. Choosing the wrong edition, or the wrong licensing scheme, could cost you thousands of dollars that you didn't have to spend.
The article continues at http://www.developer.com/db/article.php/3502746