A Pocket Space (Sometimes called a Hammer Space, extradimensional space, or dimensional pocket) is the ability to create a storage area larger than should be physically possible. Often these are only accessible by a single method, and cannot be broken into or otherwise interfered with.
Some Pocket Spaces are linked to a specific object like a bag or briefcase, others can be created as a Superhuman ability and does not have any visible physical form. These are frequently sought after for their utility, security, and general convenience.