An operating system (OS) is software that manages computer resources, controls program execution, and provides a user interface ...

The computer's master control program. When a computer is turned on, a small "boot program" loads the operating system. Although additional system modules may be loaded as needed, the main part ...

What does 64-bit operating system actually mean? Find out inside PCMag's comprehensive tech and computer-related encyclopedia.

Haiku is for those who experienced either NeXT or AfterStep and want an operating system that looks and feels a bit old school but performs faster than any OS they've ever experienced.