Why do you want to upgrade?
Here is the difference between the two.
Difference between XP Home and XP Pro
Why are there multiple different versions of XP?
XP will initially be released in two different versions: Windows XP Professional (for businesses) and Windows XP Home Edition (for consumers.) Although the kernel for both operating systems are the same, the Home Edition is a stripped down version of the Professional version. Its main focus is the consumer home PC market, and it is designed to be easier to use. Much of its interface assumes that you have a full time internet connection and that your primary online activities are browsing, e-mail, instant messaging, listening to MP3 and online music, and sharing photos and other digital media on the web. XP Professional is designed for business and advanced home users who need security and enhanced networking capabilities. It looks and feels just like Windows 2000 once you drop the XP color scheme and choose "Windows classic." Windows XP Media Center Edition and Windows XP Tablet PC Edition are special versions of the operating system designed for specific hardware. You can only get these versions when you purchase a the specialized hardware directly from the manufacturer.