Virtually nothing in the world would be possible without the presence of actuators, but few people know what they actually are. An actuator is simply a device that is responsible for the movement or control of a mechanism or other system. They use energy from a source, such as electricity, and convert it into some form of motion. Because of this broad definition, there are many things that fall under this umbrella term.
As is evident, there is a variety if actuators utilized in mechanics, engineering and other sciences. However, the term also applies to everyday things as simple as a gripping tool or light switch. Human muscles are even classified as actuators, as they convert the energy stored in the body into movement.