Windows 7 : Six versions

Microsoft Corp. said today that it will generally deploy two primary versions of Windows 7, although it will still offer six editions for sale.

The two main editions will be Windows 7 Home Premium for consumers and Windows 7 Professional for business users.

"The first change in Windows 7 was to make sure that editions of Windows 7 are a superset of one another

Reference: http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9127259&intsrc=hm_ts_head