Sparkfun Solenoids & Actuators
Solenoids are electrical components that convert electrical energy into linear motion. They consist of a coil of copper wire wound around a metal core, and when a current is applied to the coil, it creates a magnetic field that causes the metal core to move. The motion is activated by a solenoid plunger, which is typically controlled by an external switch.
Actuators are mechanical devices that transform energy into motion. They are composed of a motor, linkage, housing and other components, and they can be used to move internal valves, driveshafts and other mechanical components. When connected to a controller, they can be used to convert electrical signals into mechanical movement, such as raising and lowering a platform. They can also be used to control the speed, direction and force of the motion.