A - Captain's Office: Office used by the Captain and Executive Officer.
B/C/D/G - Docking Pylon/Docking Ring/Ring Airlock: Area of the space station where various ships can exchange passengers and/or cargo as well as make repairs.
E - Habitat Ring: Section used for living quarters for permanent and non-permanent residents of the station.
F - OPS(Operations Control Center): The command center of the station. Every system can be monitored, controlled and accessed from there. The "brains" of the station.
H - Promenade: Section used by merchants, religious establishements, schools, holosuites, and many others.
I - Reaction Control Thrusters: Used to move the station around if necessary.
J - Runabout Pad: Used for landing and launching various smaller ships, generally runabout-type ships.