Shock absorbers, linear dampers, and dashpots are devices designed to provide absorption of shock and smooth deceleration in linear motion applications. They may be mechanical (e.g., elastomeric or coil spring) or rely on a fluid (gas, air, hydraulic), which absorbs shock by allowing controlled flow from outer to inner chamber of a cylinder during piston actuation. The piston rod is typically returned to the unloaded position with a spring.  Shock absorbers typically contain both a fluid or mechanical dampening system and a return mechanism to the unengaged position. They vary from small device application to large industrial and civil engineering uses.  Linear dampers is an inclusive term that can be applied to many forms of dashpots and shock absorbers; typically used for devices designed primarily for reciprocating motion attenuation rather than absorption of large shock loads.  Dashpots are typically distinct in that while they use controlled fluid flow to dampen and decelerate motion, they do not necessarily incorporate an integral return mechanism such as a spring. Dashpots are often relatively small, precise devices used for applications such as instrumentation and precision manufacturing.