In most of the tutorials, publications and even some Docker blog posts, container engine is illustrated as an entire layer that sits on top of the OS. It is also considered as a hypervisor or a layer that does virtualization and it's even sometimes called lightweight virtualization or OS-level virtualization.
But the truth is, the apps are running on the OS directly and they all share the same kernel. The container engine does not interpret or translate any code to run on the underlying OS.
I've also read How is Docker different from a virtual machine but it's mainly about the difference between virtual machines and containers but my question is specifically about container engines.
Is it correct to illustrate container engine as an entire layer between the OS and the applications (figure 1) or it should be considered just as a process running next to other applications on top of the OS (figure 2)?
