When a company or organization wants to use the Internet, they must decide whether they want to do it by directly attaching to the Internet system or whether they will use another company to supply the connection. Many companies choose to use another company, called a service provider, because it reduces the amount of equipment, administration, and costs involved. If the company or organization wants to directly connect (and sometimes when they are using a service provider), they may want to have a unique identification for themselves. For example, ABC Corporation may want to have electronic mail through the Internet addressed to them as "abc.com." The name helps identify the company or organization to the sender.

In mid-2002, an unprecedented series of major security flaws were uncovered in Windows 2000, Internet Explorer 6.0, and IIS 5.0, which are some of Microsoft’s most strategically important products. The resulting media backlash resulted in a now-famous "trustworthy computing" internal memo from Bill Gates to all Microsoft employees. The gist of the memo was this: Stop programming and take a look at what you’re doing from a security perspective. For two months, production on all Microsoft products stopped, and Microsoft programmers and other employees attended a series of classes designed to highlight common programming practices that often result in security flaws. The programmers also reviewed the code for their products, including Windows Server 2003, with an eye toward removing those unsecure programming practices. The result, according to Microsoft, is that a huge number of security flaws were removed from Windows Server 2003 (and other products) before it was released to manufacturing.

In recent years, Microsoft has taken a pummeling in the Web server business. At one time, IIS and Windows NT Server 4.0 was the most popular commercial Web server platform; today, Windows 2000 Server and Windows Server 2003 are fighting against a wave of free and inexpensive versions of the Linux operating system and Apache Web server software. Microsoft argues that such servers don’t come with the support that a multi-billion dollar company like Microsoft can provide; fans of Linux/Apache solutions say, "Who cares?" As a result, Microsoft has worked hard to provide a lower-cost version of Windows that’s optimized to be a high-speed Web server. Although lower-cost certainly doesn’t beat free, it does help close the gap and make potential buyers look at the additional features IIS offers, as well as the support Microsoft can provide. Microsoft’s lower-cost Web server solution is Windows Server 2003, Web Edition.

Every Window object has a document property that refers to a Document object. The Document object is arguably more important than the Window object itself: while the Window represents the browser window, the Document object represents the HTML document that is displayed in that window. The Document object has various properties that refer to other objects which allow access to and modification of document content. The way that document content is accessed and modified is called the document object model, or DOM, and there are several DOMs in existence: