Control valve (also known as an automatic control valve) is a throttling valve mostly equipped with actuator or actuation system that is designed to work within a control loop. The control valve is the final control element of a process loop (consisting of a sensing device, controller, and final control element). 

Manually operated valves and pressure regulators can stand alone in a throttling application, while a control valve cannot, hence the difference, a control valve is a throttling valve, but not all throttling valves are control valves.

Generally, control valves are divided into four types: globe, butterfly, ball, and eccentric plug valves. Each design has specific applications, features, and advantages.