A linear actuator is an actuator that creates linear motion (as opposed to rotary motion, e.g. of an electric motor). The design of most linear actuators is quite simple, with a minimum of moving parts. They are self-contained, operate at high speeds and have identical behaviours for extending or retracting. By contrast, a rotary actuator is an actuator that produces a rotary motion or torque.

The simplest actuator is purely mechanical, where linear motion in one direction gives rise to rotation. The most common actuators though are electrically powered. Other actuators may be powered by pneumatic or hydraulic power, or may use energy stored internally through springs.

Hoerbiger is active throughout the world as a leading player in the fields of compression technology, automation technology and drive technology.

Exlar Corporation designs and manufactures roller screw linear actuators, rotary servo motors, and electronic products for motion control applications.

Thomson BSA is a leader for ball screws, lead screws (also called power screws), and lead screw nuts in manufacturing, design and service.

IDC - Industrial Devices Corporation, engages in designing, manufacturing, and marketing electronic motion controls and electric linear actuators for the automated machinery market. It offers rotary and linear positioning devices, including electric cylinders, rodless actuators, robotic cartesian systems, and precision positioning tables.