What is closed loop System?

A Closed-loop Control System is also referred to as a feedback control system. It uses the open-loop system as its forward path but the difference is that it has one or more feedback loops or paths between its output and its input. Put another way, some portion of the output is recovered "back" to the input to form part of the excitation of the system.

The major advantage of the Closed-loop systems is to automatically obtain and manage the desired output condition by comparing it with the actual condition.