Userspace

The user-facing code of the Linux operating system, where most user applications are run. Sits on top of the kernel in the kernelspace-userspace model. Containers are, in a high-level way, swappable userspaces that utilize the underlying host’s kernel as the backbone for privileged, system-level, kernelspace execution needs, while the applications and operating system environment presented to the user within the unprivileged userspace can be changed via the container.