An automatic door closer (more often called a "door opener") opens the door itself, typically under the control of a push button, motion detector or other device, and then closes it as well, typically employing a motion or proximity detector to determine when it is safe to close the door.
A door closer (Door Spring/Door Check) is any mechanical device that closes a door in a controlled manner, preventing it from slamming, in general after someone opens it, or after it was automatically opened (when opened automatically they are commonly referred as a door opener). The force used to open the door is stored in some type of spring and when released this energy is then utilized to return the door to its normal starting position (closed position). Many types of modern door closers can be linked to a building’s fire alarm system. In scenarios where doors need to be held open for the majority of the time for example they are held back with some sort of electro magnetic device. When the fire alarm is triggered it cuts power to the electromagnetic hold-open device allowing the doors to close. These hold-open devices can be separate to the door closer or part of its integral design
