Cargo bay

From Memory Alpha, the free Star Trek reference.

A cargo bay or cargo hold is a general purpose storage facility aboard shuttles, starships and starbases. Cargo bays are often equipped with large transporters to assist in the moving of cargo containers. However, aboard Galaxy-class starships, cargo bays located in the stardrive section do not have transporters. In that situation, cargo was directed into the bay by a transporter chief operating in a transporter room. (TNG: "11001001", "The Child")

Cargo bays have been used in a variety of ways other than typical storage, including triage centers, brigs, and stasis unit facilities.

USS Voyager's apparently had several bays with the designation "cargo bay 2". One had variable environmental controls and was designed for organic storage. It was converted to a hydroponics bay by Kes in 2371 in order to allow for the growth of foods for consumption. Another was located on deck 4 and suffered a massive hull breach when a Kazon shuttle intentionally collided into it in 2372. In 2374, the Borg assimilated yet a third "cargo bay 2" during an alliance with Voyager. After the alliance, four Borg alcoves remained in the bay and it went back to normal cargo storage. This "cargo bay 2", however, was located on deck 8. (VOY: "Parallax", "Scorpion, Part II", "Equinox", "The Gift")

Cargo bay 4 aboard the USS Enterprise-D was located close to the outside of the ship and could be decompressed easily by blowing the cargo bay hatch. (TNG: "Power Play")

Miles O'Brien used one of Deep Space 9's cargo bays to install a dart board in 2371. (DS9: "Prophet Motive")