What is an operating system, and what are its main responsibilities?
Interview preparation resource from Gate Smashers.
An operating system is system software that manages hardware resources and provides safe, convenient services to applications. It acts as the controlled bridge between programs and the hardware.
Without an operating system, every application would need to understand the details of the processor, memory, disks and input/output devices. The OS hides those differences behind standard abstractions such as processes, files, sockets and virtual memory.
It also decides how limited resources are shared. The scheduler distributes CPU time, the memory manager assigns RAM, the file system organises persistent data and device drivers communicate with hardware. Protection mechanisms prevent one program from reading or damaging another program's data.
A useful way to remember the OS is as both a resource manager and an abstraction provider. It manages the physical machine while presenting simpler logical views to programs, allowing applications to remain portable and users to run many tasks safely at the same time.