On July 29, 2015, Microsoft will finally ship the desktop version of Windows 10 for PCs, tablets, and laptops. However, this doesn’t mean that the work will be over; it’s just the beginning. The new version of the operating system is the start of “Windows as a Service”. That means there will be ongoing updates with security patches and new features as soon as they become available, instead of big releases like previous version of Windows.
Source: iMore