An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs.
An IBM System 360/65 Operator's Panel. OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.
The first server for the World Wide Web ran on NeXTSTEP, based on BSD.
Computer hardware includes the physical parts of a computer, such as the central processing unit (CPU), random access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a monitor, mouse, keyboard, and speakers.
PDP-11 CPU board
Inside a custom-built computer: power supply at the bottom has its own cooling fan
Computer motherboard
An IBM System z9 mainframe