The spring is a kind of spring that, when the watch is wound, winds up to a maximum stop, and as it unwinds, it provides movement to the hands. As the spring cannot be wound infinitely, automatic watches have a mechanism that causes the rotor to disengage and stop winding it when it reaches the stop.
An automatic watch is a mechanical watch that was first marketed in the early decades of the 20th century. It works automatically when worn on the wrist, eliminating the need for manual winding. However, if it has not been worn for a period of time, the watch will stop working and will require manual winding.
As you can see, automatic watches are charged just by using them. However, when they are no longer used, the watch will most likely stop and that is where it is important to give it a little wind to start it.