What is the lock?

The lock is a device that ensures the opening and closing of your armored door.
It's a sort of box that controls pins that fit into your door frame.

There are various types and each has varying degrees of safety (and 1 a 3), it may indeed be mechanical o electric o electronic. From the simple lock for internal doors and cellars equipped with a key not encrypted, to the lock on wooden doors whether applied or recessed with a flat encrypted key, to the safety lock for security door with double bit key, to the reprogrammable magnetic card lock typical of some hotels.

What is the cylinder?

The cylinder is the heart of the lock: it is an instrument composed of a central body that moves and controls the lock mechanism. It is a very important component because if the thief manages to remove the cylinder, the door no longer has protection and with a simple screwdriver you will be able to open it.