The Prusik Knot is a type of climbing knot used to create a movable anchor point on a rope. It is particularly useful in situations where a climber needs to ascend or descend a rope, as it can slide when not under load but tightens when weight is applied. This makes it an essential tool for climbers, rescue operations, and cavers. To tie a Prusik Knot, a loop of rope is wrapped around the main rope and then threaded through itself, forming a secure grip. The knot is named after Karl Prusik, an Austrian climber who popularized its use in the early 20th century.