In days gone by, Windows released major changes to its operating systems by assigning them version numbers. For example, the major upgrade to Windows version 2 was Windows version 3. When version 3 was itself upgraded, it was given the title Windows Version 3.1.
Today, the terminology is a little different. Rather than calling this newest update "XP 1.1" or "XP Second Edition," it's called "XP with Service Pack 2." The end results, what-ever the designation, remain the same. This is a major update both in the way the operating system works and in the technologies that are enabled by default.
For example, the Internet Connection Firewall was an optional component in XP… I'm not even sure what to call it… XP alpha… original XP? Sure, let's go with that. Now, with XP SP2, the Windows Firewall is installed and actively protecting your computer the instant you make the upgrade.
Also, this chapter is just an introduction to the new features and changes brought about with SP2. Because the new technologies are so integral to the ways you use the operating system, SP2's new features will be on display throughout the book. For example, Chapter 10, "Setting Up a Wireless Connection, or How to Check Your Email in a Coffee Shop," could also be described as a corollary to this one. When dealing with a wireless network, it's almost all new. Another example: the Windows Firewall affects both how and if you can share out resources on your network; I'll identify the Firewall's configuration requirements in Chapter 9, "Playing Nicely with Others."
In other words, even though this book is first and foremost about Windows XP, we're nowhere near finished with the discussion of Service Pack 2. Stay tuned.