How can a key that cannot unlock a door fit into the lock? But when you try to turn it to open the door, it does not open?

Question

Title.

In: Technology

Answer 1

There are two parts of a key. One is the grooves that run lengthwise down the body to create a profile that determines whether it fits into the keyhole. The other is the teeth on the key that determine whether it actually engages the tumblers inside the lock.