In earlier versions of ProxMox the openvz vms were called containers and the KVM vms were called vms. So it is pretty confusing overall.
For myself I would point out that Zones, Jails, OpenVZ and LXC , even KVM, all pretend that they are fully separate from the host node OS.
While Docker et al do not pretend this; in fact if you are running Apache on your host system and try to run a Dockerized web server on port 80 the Docker container might refuse to start. The other methods mentioned, can't even determine what they are running under.
Sorry for not being clear ... the OpenVZ, LXC, Zones (not sure about Jails) all have their own startup options, and if they don't start "init" as the first process inside, then they have a method that fakes it. You can install random new packages of software and run them, from inside the "VM" - from what I know, you can't do this from within a container.
FWIW using KVM all you can see from the host node (unless you use debugging tools) is the PID and related process info of the KVM instance (one process per VM you have started).
Hm, that isn't what I am trying to say at all. In drawing a distinction, some of the virtualization tech acts like a full blown OS in and of itself, while others do not. x
For myself I would point out that Zones, Jails, OpenVZ and LXC , even KVM, all pretend that they are fully separate from the host node OS.
While Docker et al do not pretend this; in fact if you are running Apache on your host system and try to run a Dockerized web server on port 80 the Docker container might refuse to start. The other methods mentioned, can't even determine what they are running under.