The half hitch is one of the simplest knots. It isn’t stable on its own, but we use it frequently as a component of larger ties.
The half hitch is a key component of many other knots, including the aptly-named round turn and two half hitches.
We often use the half hitch to secure the rope when finishing a harness.
The single hitch (ABOK 1594) is a different knot but we usually call it a half hitch. It is frequently used to join one rope to another at an angle.
1Go under and around the pole.
2Go under the standing part.
3Go back over the standing part and under the working end.
4Pull the half hitch snug.
This knot is ABOK # 48
A single hitch (aka a half hitch) joining a rope to a pole at a 90° angle.