What is an operating system?

• A. A program that runs only applications
• B. The software responsible for controlling or communicating with computer hardware
• C. A compiler for programming languages
• D. A utility for editing text

Answer: (B)

An operating system is the software layer that manages hardware resources and provides services to programs. It sits between applications and the computer’s components, coordinating the CPU, memory, storage devices, and input/output peripherals. By handling process scheduling, memory allocation, device drivers, and file systems, it enables multiple programs to run at the same time safely and efficiently and gives programs a consistent interface to interact with hardware. It also offers user interfaces and runtime services that applications rely on. The other descriptions miss essential parts of what an OS does: a compiler translates code, a text editor is just a utility for editing text, and a program that runs applications alone doesn’t cover the hardware management and resource coordination that an operating system provides.