A storage locker is a place where people can secure their property.

The assay office aboard Deep Space 9 had several storage lockers which were secured by individual force fields, a personal authorization code, and a verified retinal scan. (DS9: "Q-Less")

The archaeologist Vash stored her property she brought from the Gamma Quadrant in cubicle 19. (DS9: "Q-Less")

Morn kept a brick of gold-pressed latinum in storage locker 137. (DS9: "Who Mourns for Morn?")