Both. Here is the difference from
newegg
Windows 8 - This is the main edition of Windows 8, which is targeted at home users. It's most similar to the "Home Premium" edition of Windows 7. With Windows 8, you get all the features you'd expect - the Windows desktop with support for traditional Windows desktop programs, the new environment formerly known as Metro, and other features designed for home users. Most people will be happy with this edition of Windows 8.
Windows 8 Pro - The Pro version is targeted at businesses and enthusiasts. It includes the kind of features traditionally included in professional editions of Windows: group policy support, remote desktop server capabilities, Windows domain support, encrypting file system, virtual hard disk booting, and BitLocker. There's one feature that might interest some of you here, though - you can only use Windows Media Center on Windows 8 Pro. It's available as a free add-in, but only for the Pro version of Windows 8.