Starfleet officers have ranks similar to Earth's Naval forces, and follow the Chain of Command, but they are not a military group. There is one law all Starfleet officers are required to follow called the Prime Directive. It says that members of Starfleet are not allowed to interfere (become involved in) the way a primitive society develops. Starfleet officers are trained at Starfleet Academy, located in San Francisco. Starfleet officers are given orders by Starfleet Command, located on Earth.