There is plenty of info on Kubernetes (K8s) on the web, so I would start there. As far as running K8s inside Docker containers though, the use case would be one in which you want to run multiple isolated K8s clusters on a single host. One way is to use VMs, but recently people are resorting to using containers for this purpose due to their ease & efficiency. It's in the latter that Sysbox really helps, because it's capable of creating a container that runs K8s easily and with proper isolation. Typical use cases are testing, CI/CD, learning. But I would not discount this moving into production use cases in the future as the technology matures.