These services allow the client to control the server entriely.
You Provide the Rackmount server we provide the Rack space power and the connectivety.
Alternatively we can provide you with your own independent rack allowing full manageablity by yourself.
We can also provide additional services to complement your colocated equipment including:

Maintenance and Support
Tape Backups
Firewalls
Leased Lines
Configuration and Remote Assistance