(give it a few seconds to kick in)
The animation shows the principles of how a lever lock works, it might also be called a mortice deadlock or a "chubb type" lock. The lock shown has one lever for simplicity, although front door locks commonly have 5 levers. The key is inserted in the keyhole and turned, as the key turns it lifts up the lever against its spring to the correct height so that the bolt stump (which is part of the main bolt) can pass through the lever gating. As the key continues to turn it pushes the bolt horizontally into the "bolthole" or "keep" which is cut into the door frame. When the key has fully "shot" the bolt, the lever then drops leaving the lever gating blocking the bolt stump. The lock is now deadlocked.
