The bowline is a knot that forms a fixed loop at the end of a rope, used by some climbers as an alternative tie-in and to attach the rope to anchors or trees. Its main advantage over the figure-eight is that it unties easily even after heavy loading, but it must be backed up, since an unsecured bowline can shake loose.
Climbing knots are the small set of knots, hitches, and bends that climbers rely on to tie into the rope, build anchors, rappel, and perform rescues. A handful do almost everything — the figure-eight to tie in, the clove and munter hitches at the anchor, and friction hitches like the prusik for ascending and backups.
A prusik knot is a friction hitch tied with a thin loop of cord around a climbing rope. When weighted it grips the rope and holds; when the load is released it slides freely by hand. This lets climbers ascend a rope, back up a rappel, or build a hauling system for crevasse rescue.
The figure-eight follow-through is the standard knot climbers use to tie the rope into their harness. It is strong, easy to inspect at a glance, and holds securely under load, which is why it is taught as the primary tie-in knot worldwide. Climbers finish it with a backup or stopper knot.
A clove hitch is an adjustable friction knot that climbers tie directly onto a locking carabiner to attach themselves to an anchor. Its key advantage is that the length can be fine-tuned with one hand after tying, without untying the knot, making it the standard way to clip in at a belay station.