Linux Kernel, Kernel, The Kernel

Firstly, the low-level code that powers the Linux operating system. All Linux distributions are ultimately based on the same kernel, which is open source and located on GitHub at https://github.com/torvalds/linux. The kernel is developed by a vast number of community contributors both past and current, with discussion around this development primarily done on the long-running Linux kernel mailing list.

Secondly, the space of a Linux operating system in the kernelspace-userspace model where the operating system runs its privileged system-level operations like interacting with the computer’s hardware, drivers, and administrative functions. Accessible by default to the root level account, with sudo being used to provide configurable access to other users.

Containers allow for swapping out the userspace of a given running host without needing to change the running kernel.