It's not a service as I would think of it. You download and install it on-premise as far as I understand.

I know they call it "CaaS", but I guess they are comparing it to using other PaaS's that can be installed on-premise, such as Cloud Foundry. Personally I find the term confusing, as I'm not sure who the consumer of the service is meant to be (developers creating containers? ops who get a platform for running them?)