There are two types of jumps in the world of National Hunt Racing: Hurdles and Steeplechase fences.

Hurdles are relatively small and are usually the jumps that young or inexperienced horses start over:

The next size up are steeplechase fences, which are usually for more experienced horses:

There are even bigger, wider steeplechase fences that are used for more experienced jump horses and jockeys:

And finally, there are enormous steeplechase fences which are covered with up to 3 foot of spruce to make them seem even bigger. These fences are reserved for the best and most experienced horses and jockeys who are able to jump into the Grand National: