The differences are not very big and casual home users will find XP Home Edition sufficient.

Windows XP Professional Edition has the following differences:

Administrative Tools in the Start Menu and Control Panel
Automated System Recovery
Boot Configuration Manager
DriverQuery
Group Policy Refresh Utility
Multi-lingual User Interface (MUI) add-on
NTFS Encryption Utilitiy
Offline Files and Folders
OpenFiles
Performance Log Manager
Remote Desktop
Scheduled Tasks Console
Security Template Utility
Taskkill
Tasklist
Telnet Administrator

XP professional also provides support for multi-processor systems (several CPUs), Dynamic Disks and Fax.

More Cool Windows XP tips & tricks HERE