The Autoblock is used during rappelling as a safety knot to stop you in the event of a fall. It is also used in many rescue techniques.

 

The Butterfly Knot is used to tie someone in on the middle of the rope (not at an end).

 

The Clove Hitch has many uses, including equalizing anchors.

The Daisy Chain is a compact, easy way to store and carry webbing.

The Double Bowline is used for a tensioned knot in a top rope anchor. Some people also use it to tie in (instead of the figure 8) because it is much easier to untie after falling on it. But, don't forget that people call it the "death knot" for a reason. This knot MUST be carefully tied and verified. Until you are very comfortable using it, try the figure of eight knot instead.

The Double Fisherman's Knot is used to tie two pieces of rope together. Do not use this to attach to ends of webbing (use the water knot instead).

The Figure 8 "follow through" is used to tie into the rope. This knot is preferred since it is so easy to tie and double-check. I should mention that untying the figure of eight after you've fallen on it (because your hands are simply too pumped to work at all anymore) is a bitch... "Hey... Can somebody help me with this knot? I can't move my fingers!" Another useful "tie-in" knot is the double bowline.

The Figure 8 on a Bight is used to tie into an anchor.

A Figure 8 Inline knot can be used to tie someone in (or anchor) from the middle of the rope.

The Girth Hitch is a standard knot used to attach a loop (sling or rope) to some anchor.

The Münter Hitch is used to belay someone (usually the second).

If you click on this picture, notice the H.M.S. inscribed on the 'biner.
Always use a "pear-shaped" locking 'biner for the Münter Hitch.

The Prusik is used as a saftey knot during rappelling. It is also used to ascend rope and in rescue work. For safety, I suggest always wrapping your Prusik knot three times (not two).

 

The Water Knot (AKA: Ring Bend) is an overhand with a follow through. It is primarily used to tie two ends of webbing together. Always back this knot up with a Grapevine (half a Double Fisherman's Knot).

 

The difference between a knot and a hitch is that a knot always holds its form, whether it is being used or not (no pun intended). A hitch on the other hand has to be wrapped around something to keep its form.