It is a rack of servers, but, every aspect of it is supposed to be engineered to include the full list of things that are needed to make a rack of servers a useful VM hosting setup. So it includes the networking, connection to the service processors which allow you to remotely access each server, other management things, etc.
Once installed, you plug in the network connection(s) and add power, then boot up. Then you can add your VMs and start running them.
Once installed, you plug in the network connection(s) and add power, then boot up. Then you can add your VMs and start running them.