A fingerlock is a specialized finger jam where the climber opposes his thumb and forefinger in a narrow crack, creating a solid lock so the fingers don't come out easily.
When climbing, you wedge your fingers in a narrow crack to make progress vertically, where you then oppose your thumb and forefinger inside that crack.
A finger lock is secure finger jam used in climbing. The person opposes his thumb and fore finger in a narrow finger-sized crack, thus creating a lock.
