Containers are the process and environment isolation facilities of the OS. It just turns out that sometimes it's useful for processes to see each other, and oth

Containers are the process and environment isolation facilities of the OS. It just turns out that sometimes it's useful for processes to see each other, and other times it's detrimental. Similar for chroot and filesystems (for environment isolation). It turns out that containerization is nothing more than extremely fine grained control over what processes get to do what in a running system. The name for a fully isolated process/environment is "container" is all. Docker currently, for the most part, creates a basic userland for use within a container, however LXC doesn't require that at all - instead you can just link the existing userland FS into a directory tree. Heck docker even allows this, but it's harder to do some things than others.