Though its still early to celebrate… I’m proud to announce Microsoft’s release of Windows 10. Why Windows 10 and not 9? I was also as confused as you are. However, the release video made a legit elaboration. Windows 10 wasn’t an evolution of the Windows 8 but was out to converge a platform for users from both Windows 7 and Windows 8.
Windows 10 is probably going to be the most compatible software because of it’s large array of target devices. Simple improved features such as customising the start button experience, better modern security both online and offline, one store with customised apps suitable for your respective device. For now the built is still in a testing stage as they engage users to find faults and kinks.