Kernel (operating system)

The kernel is the central, fundamental part of a computer's operating system. It is the main program that manages the system's hardware resources and provides essential services that allow other parts of the operating system and application software to run and communicate with the hardware.

The kernel acts as a bridge between the hardware and the software. It runs in a privileged mode (often called "kernel space" or "supervisor mode") that gives it direct access to all hardware resources, while applications typically run in a less privileged mode (user space). Applications request services from the kernel through a defined interface called system calls.

Overview

The kernel is loaded into memory when the computer starts up and remains resident in memory until the system is shut down. It is responsible for the most critical low-level tasks. Because of its privileged access and central role, a crash in the kernel typically causes the entire system to become unstable or crash.

The specific functions and architecture of a kernel vary depending on the operating system design, but its core purpose is always to facilitate the interaction between software and hardware in a safe and efficient manner.

See also

• Operating system