Even embedded systems run on an OS, wondering of the GP knows that Ubuntu is running Linux (ie, an OS) under the hood.
And that Kubernetes deployments out there primarily run on Linux.
And that Kubernetes deployments out there primarily run on Linux.
No, not all embedded systems run an OS. Linux is not an OS, it's a kernel. Ubuntu is an OS. Kubernetes is application software that runs on several operating systems, primarily ones based on the Linux kernel.
Ubuntu is not an OS, it's a Linux distribution.
Many do not. I've seen quite a few ARM processors running without any OS.