Pods were usually devices employed to contain, and/or transport, living beings.
Escape pods were commonly attached to spaceships, fulfilling the same function as a lifeboat would for a sailing ship. (TV: The Fires of Pompeii, AUDIO: Empire of the Racnoss, COMIC: The Lost Dimension, etc.)
Supergirl came to Earth in a pod rather than a spacecraft. (WC: Supergirl Meets E.T.) Morpheus pods were a 38th century invention which allowed whoever lay in them to simulate the human body sleeping a whole night in just a five minute period. (TV: Sleep No More)
Seed pods were used by the Ice Warriors. (TV: The Seeds of Death)
In the year 5000000000, pods were used for racing. One particular pod, the Hyposlip 500 Lightspeed-Podule, was debuted in this year, and was highly coveted for its Hyposlip Travel System technology. (COMIC: Death Race Five Billion)