Struts are part of architecture, also, as they are used very much nowadays in buildings made with structural steel. Along with stanchions (columns), struts are structural elements which contribute necessary support for "compressive loads" along their longitudinal axes. Struts and columns are present in buildings from ancient times as they are found in temples built thousands of years ago, and are yet in frame structures today, and certainly with large buildings and skyscrapers.
In fact, on all buildings there are certain forces upon them: tensile, comprehensive, and shear forces. The part of the construct that has a tensile force acting upon it is called a tie, while the part that has a compressive force is called a strut. On a roof, for instance, the struts are the peaked (upside down "V" shape" upon which the roof tiles are placed.
Discussions of struts usually involve automotive mechanics, although they are used in engineering projects in general and comprise a component of the structure’s stabilization system. Automotive struts are part of the “front-end” of an automobile’s suspension system. A car’s suspension system is designed to prevent the vehicle from being jarred out of control on especially rough roads or when the operator drives over a pothole, speed bump, or other obstruction. Automotive struts, including the thick spring, are frequently structured around a shock absorber, which minimizes driver impact from bumps and potholes. Struts are also commonly used on smaller aircraft to support the wing structure. By connecting the wings to the fuselage of the aircraft (i.e., the aircraft’s “body”), struts greatly strengthen the wing’s against higher levels of pressure the pilot may encounter. Wings, of course, are attached to the fuselage at the base of the wing, but struts provide additional support mechanisms. If one were looking at the exposed wheel of aircraft, or were positioned under a car, one would see thick bars connecting the wheels to the broader structure. Those bars are the struts, and comprise a major component of the overall stabilization system.