Electronic Access refers to locking systems that are remotely controlled, typically through a keypad, biometric sensors, or using a buzzer.
This keypad is an example of a device that might be used to control and electronic access system.
Electronic strikes are often the functional basis of an electronic access system. They allow a door to be opened without retracting the latch. The door can be opened with either a key, or using the electronic releases system (keypad, buzzer, etc.). In the below photos, the silver part between the black clamp is on a pivot, controlled by a powerful magnet.