Comparison of Windows 7 Starter, Home Basic / Premium, Professional, Enterprise and Ultimate

Windows 7 was officially released almost a year ago, but maybe some do not know about some of the editions of Windows 7 which is more outstanding. Not infrequently new laptop came with Windows 7 Starter. Do what difference this edition with the other? There are at least 6 edition of Windows 7, namely: Windows 7 Starter, Home Basic, Home Premium, Professional, Enterprise and Ultimate, then what's