Escape pods are onboard Fleet ships for emergencies when the crew must abandon the ship. There are several types of escape pods; some of which are more like small shuttles, whilst others being completely different in shape.
Escape pods were seen onboard the Rodger Young when the ship is torn in half by Plasma; these Escape pods resembled shuttles, but smaller in size (carrying two personnel). It may be assumed that personnel with flight training would have been the main users of these particular pods.
Onboard the Geronimo when the ship is heavily damaged, several crew members are able to enter a much larger escape pod that was spherical in shape. This pod contained enough room for a minimum of six personnel and appeared to be a more basic design for large groups of crew to abandon ship. Ironically or not, it matches the design of Vostok re-entry module — the first manned human spacecraft.