Command Center is the main building of the colony.
The Command Center is the only building any colony will have when a new game is started. The building acts as the primary objective of Survival Mode, in that the main goal is to keep this building alive. If the Command Center gets destroyed or infected, the game is lost.
From here, you build any other building in the game. It is therefore, apart for being your main focus, also the most useful building. Only a limited number of buildings are available from the very start, as some require additional Research to unlock.
The Command Center also passively provides 200 gold every 8 hours, 20 food and 30 energy, with an energy transfer radius of 10. Additionally, the Command Center has a Storage Expansion of 50 and comes with 10 workers.