Containers are interactive objects that hold other objects. Most allow items to both be removed or deposited. Containers in the Fallout universe defy physics by being practically unlimited in capacity. Items left in public containers for long periods of time may disappear either through attrition or NPC looting.
Some containers share identity in that items deposited or removed in one will also be deposited or removed in another. Whether this is due to a bug or due to coding design to save game resources is unknown.