Tensegrity is a portmanteau of tensional integrity. It refers to the integrity of structures as being based in a synergy between balanced tension and compression components. Tensegrity structures are built of struts and cables. The struts can resist compressive force and the cables cannot. Most cable–strut configurations which one might conceive are not in equilibrium, and if actually constructed will collapse to a different shape. Only cable–strut configurations in a stable equilibrium will be called tensegrity structures. If well designed, the application of forces to a tensegrity structure will deform it into a slightly different shape in a way that supports the applied forces. Tensegrity structures are very special cases of trusses, where members are assigned special functions. Some members are always in tension and others are always in compression. A tensegrity structure’s struts cannot be attached to each other through joints that impart torques. The end of a strut can be attached to cables or ball jointed to other struts.