How to tie knots? Explanatory diagrams.

Figure-eight knot

For tying in

Figure-eight knot

For the anchor

Flat overhand bend

For joining two ropes

Bowline knot with backup knot

Easier to untie than the figure 8 knot
WARNING: backup knot mandatory (e.g. with a double overhand knot)

Clove hitch

Rapid-adjust anchor knot

Munter hitch

Friction hitch, does not lock the rope

Double knots

Used to equalize anchors when installing a fixed vertical line or traverse line.
The bowline on a bight can be easier to undo after significant loading.

Bunny

Bowline on a bight

Butterfly knot

One of the few knots that minimizes rope strength loss, this knot may be used to isolate a damaged section of rope.

It can also be used to equalize two widely separated anchors in conjunction with a figure 8 knot.

【转自：https://www.petzl.com/US/en/Sport/Knots?ActivityName=Rock-climbing】