What is the difference of open or closed-loop control?

I will give you an example to understand about open loop control system and closed loop control systems.

Suppose we are flying a kite. If we want the kite to go higher then we have to loose the thread first and then immediately pulling the thread so that it can go higher. Here, loosing of thread and pulling of thread is the input to the system and the decision of pulling and loosing is coming through feedback and with this the kite is controlled to fly in the sky.   Now here, Input = through thread, System = kite, feedback = eye and output = happily flying kite, so this type of controlled system is known as closed loop control system.

Now come to open loop: Suppose we are considering the same system of flying kite. This time we are going to face the kite from the back side and there is no connection of eye with the kite, means that either loos the thread or pull the thread, it is not in your hand to make a stable fly or one can say controlled fly of the kite. Now here, Input = through thread, System = kite, feedback = no feedback and output = unhappy flying kite, so this type of controlled system is known as open loop control system.

Hope this explanation will help you to understand about open and closed loop control system

the closed loop control differs from the open loop in a way that a feedback from the output is used to update the control input. whereas, the open loop control generate the input without reading back the output to modify the next input.