Windows 7 Professional

Windows 7 Professional is the second Windows 7 edition next to Windows 7 Home Premium that Microsoft will be available for customers and OEMs worldwide.
This edition would basically have been Windows 7 Business but was renamed by Microsoft to reflect that it is not only aimed at business but also at professionals.
Some say that it was done to make the decision for Windows XP users easier to switch to the new operating system as one of the Windows XP editions was named Windows XP Professional.
Windows 7 Professional contains all features that Microsoft has build into Windows 7 Home Premium plus the following:
Windows Server Domain support.
Remote Desktop Server support.
Location aware printing.
Encrypting the file system
Presentation mode
Windows 7 Enterprise / Windows 7 Ultimate
Windows 7 will not include the following feature set which is exclusively available in Windows 7 Ultimate and Windows 7 Enterprise:
AppLocker.
BitLocker Drive Encryption
BranchCache Distributed Cache
DirectAccess
Multilingual User Interface Pack
Virtual Hard Disk Booting