There are several different door lock types with different lock tongues that include spring latch, deadbolt, and latch with hooks. The most common door lock type is with spring latch. The beveled design of latch and the spring part of latch are convenient for closing door. On the other hand, the bevel spring latch is a low noise design that reduces the operating noise to a minimum.
However, people invented deadbolt because spring latch is very easy to be cracked. Deadbolt cannot stick out automatically, either cannot retract by the power from outside due to without spring part. Deadbolt is controlled by lock and unlocks operation. The fixity of deadbolt is very strong, that’s why a lot of door lock types pair spring latch with a deadbolt for safety.