Building blocks (toy)

The Lego system is the most widely used clamp building block system in the world.

Building blocks (also construction blocks) are modular construction parts, usually made of plastic, which can be assembled in a form-fit manner. The basic components are usually cuboid-shaped, cylindrically studded at the top in a grid pattern, hollow-bodied at the bottom and smooth at the sides. The structured upper surface interacts by friction and positive locking with the correspondingly negative lower surface of other clamping components, so that complex designs can be assembled. The design allows the parts to be connected with compressive force and the blocks to be clamped with plastic pins.