[ovirt-users] Re: What do some of the terms mean in the documentation?

So in the documentation it says that the oVirt Engine is a user interface and a REST API endpoint. Ok, that's clear enough. As far as the oVirt hosts there are two types Enterprise Linux hosts and oVirt Nodes. Do the Enterprise Linux hosts run the VMs for my apps or the oVirt nodes? What are their respective roles? Do I need both?