The bowline is used for making an eye in a line. This versatile knot is used in almost every culture known to man. It is both easy to tie and easy to untie.
While making the knot, the eye could be passed around or through an object such as your waist, a ring, a rail, a tree or branch, or almost anything else that you need to, if you have enough line. The knot will tighten when pressure is put on the standing part of the line, yet is still easy to untie.
Flip a loop (round turn) in the standing part of your line, with the standing part being on the bottom side of the round turn.
Bring the bitter end up through the round turn.
Wrap the bitter end under and around the standing part of the line.
Tuck the bitter end down through the first round turn you made.
Snug it up and you have the bowline.
If you remember the following ditty, you should have no problem tying this knot:
"The rabbit comes out of the hole, goes around the tree, and dives back down the hole". The rabbit is the bitter end, the hole is the round turn, and the tree is the standing part.
This knot is used by just about every profession that uses rope or line of any size from steeple jacks to sailors, cowboys to riggers and Firemen to climbers just to name a few. The bowline is fast, easy, and secure, to say nothing about versatile.