Block stacking is a very basic form of storage, in which objects are placed on a surface (usually a flat floor) and stacked on top of each other in blocks. The clearance area can be various heights, up to several meters.

The items rest on a supporting surface and directly on the items below them. A flat floor is usual, but the definition does not require a particular base surface.

A stacking-rack system places the stacks within shelves. Block stacking instead describes the blocks of material stacked on the surface itself.