Springs can be classified according to the nature of the forces they experience: compression springs, extension springs, torsion springs, and bending springs; by shape, they can be divided into: helical springs, spiral springs, plate springs, disc springs, ring springs, and shaped springs; by manufacturing process, they can be categorized into cold-wound springs and hot-wound springs; by material, they can be divided into metal springs, plastic springs, rubber springs, and springs made of other materials.

Springs work by producing significant elastic deformation through their own action. Their applications in various machines are very extensive. Their main functions are:

1. controlling the motion of machinery, such as springs that control the opening and closing of cylinder valves in internal combustion engines, and control springs in clutches;
2. absorbing vibration and shock energy, such as dampening springs in various vehicles and springs in various shock absorbers;
3. storing and releasing energy, such as clock springs and bolt springs;
4. measuring the magnitude of force, such as springs in spring scales and force gauges, etc.