OS = option select. This term is usually used for a combination of button inputs which allows the player to cover more than one option, effectively forcing the game to automatically perform the best outcome for each of those options.

Windows 10 is the best Windows operating system for gaming. It was specifically designed with gamers in mind, and it offers a number of features that make it ideal for gaming, including: DirectX 12: DirectX 12 is a graphics API that offers a number of performance improvements over previous versions of DirectX.