What is the Bowline Knot?
The bowline is a very simple knot that is being used to form a fixed loop at the end of a rope. It has the big advantage that it doesn't jam after being loaded and is always easy to untie. If you only want to learn a few knots I'd say at least take the time to learn the bowline. The bowline doesn't come undone when it's loaded and it's almost impossible to undo it when under load. When the load is released the bowline is easy to untie again.
What is the Bowline Knot used for?
The bowline knot is great for outdoor activities like camping and boating, or arborists performing tree work. It is also great to know how to tie a bowline knot in emergency and survival situations. The loop formed by the bowline can for example be used to tow a car or another vehicle. But it can also be used to attach a cooler or backpack and then hoist it up into a tree to keep it away from bears and other uninvited guests.
Remarks
The biggest advantage of the bowline is that it doesn't jam up after being loaded, so it's very easy to untie.
The bowline is not recommended as a tie-in when climbing, because due to its form it might work itself loose. If you want to use the bowline as a tie-in then you should use the Yosemite tie-off to secure the working end.
There are a few mnemonics to help you remember how to tie the bowline knot. One of them is: the snake comes out of the pond, goes around the tree, then dives back into the pond. Where the snake is the working end and the pool is the first loop that is formed when tying the bowline knot. The standing part is the tree.
A common mistake when tying the bowline is that it's being tied inside out. When the working end ends up on the outside of your loop then you know that you have tied it wrong.