kernel
termprogrammingops culture
The part of an operating system that runs with full hardware privilege, mediating memory, processes, devices and the network for everything else.
The privilege boundary is the point. Ordinary programs cannot touch hardware directly; they ask, through system calls, and the kernel decides. That is what makes isolation between processes possible, and it is why a defect inside the kernel is categorically worse than one in an application: there is nothing above it to contain the damage. It is also why so much security engineering is about reducing what runs there - drivers moved to user space, filtering done in constrained virtual machines, and hypervisors adding a layer beneath it.
Also known as: kernel space