Command Center

"The Command Center is the heart of your base. Your Command Center level determines what buildings you can build, how many you can have, and how much you can upgrade them. It lets you create and join alliances with other players, and provides a small vault for Red Mercury and Supplies."

Stats
the command center is the place you go to manage your Alliance, request troops and parts during raids 

Resource and Army Buildings Available
Upgrading your Command Center unlocks the following number of Resource Buildings and Army Buildings, see the page for each building for details.

Defensive Buildings Available
Upgrading your Town Hall unlocks the following number of Defensive Buildings, see the page for each building for details.

Resource, Army and Other Buildings Max Level By Command Center
Upgrading your Command Center allows the following buildings to be upgraded to these levels; see the page for each structure to learn what each upgrade brings:

Defensive Buildings Max Available Level
Upgrading your Command Center unlocks the following level of Defensive Buildings, see the page for each building for details.