Some objects and enemies in the game will make the Sword recoil when you hit them, knocking Link back a great deal. If you're standing near a ledge, the recoil will cause Link to jump high in the air.
Depending on the position of the object, Link might Recoil Jump in a certain direction, or Recoil Jump in place and land back where he was. While the first case might grant you access to other areas by itself, the second case needs a little help from Bombs to be useful.
By placing a Bomb near you before you perform a Recoil Jump, you can get damaged at the start of your jump and get pushed on top of things or past others. The timing required to pull this off is very precise, but is a bit more lenient if you're using the Nice Bombs. This method is currently used to skip the Lorule Castle Trials.
Due to the specific conditions to do this technique, not many skips have been found. The timing is also very precise so some of these skips are hard to do.