Wira original one is like a motor, it actuates the door lock rod by rotation. It's quite reliable and hardly fails.
The ones that accessory shops install are solenoid actuators that move up and down. The 5-wire version is usually used for the driver-side door because it can return a signal when you pull up or push down the door lock, to tell the central locking system to lock all doors or open all doors. The other 3 wire actuator is for the rest of the doors, whereby they only push or pull. You can use the 5-wire actuators for all doors, but only connect the signal return at the driver door.
If you have a screwed-up central locking controller, the solenoid actuators have a tendency to oscillate, shooting up and down rapidly.