An escape pod does exactly what you would think it does. It's a way to escape an exploding ship, and it's a pod.
An Earth Human Escape Pod seats 20, has a crew of one (the pilot), and is a one-time-use ship. It has no weapons and no defence systems. Just 15cm of titanium. It has built-in air brakes, a parachute and little wing flaps that all control where and how hard it lands. It also has about three hour's worth of chemical-based rocket fuel, for manuvering the pod into a planet's gravity well (or into a ship's docking bay).
Generally speaking, the pod doesn't survive landing, although they only have a 2% mortality rate (as opposed to the 100% chance of death if you didn't use the pod).
Escapse pods are oblong in shape, and are initially shot out of a ship much like a blowgun dart.
NOTE: Evey militay ship in Earth's navy has enough escape pods to transport 1.25 times it's maximum capacity. The reason these aren't mentioned is because there is literally no military ship from Earth that doesn't obey that rule.