Remember how 離れる means "to separate," where something separates or moves away from something else? Well, 離す is the transitive version, so it takes a direct object and means to separate something. You can remember this because if you try to separate two people who don't want to be separated, they might sue (す) you in response!

離す is used when you detach or put space between people or objects. This could be literal, like when you 離す your bed from the wall, or more figurative, like when you carelessly 離す your eyes from something important.

It can also mean to let go of something, because you're "separating" your hand from it. This use is very similar to 放す, but it doesn't have that nuance of setting something free — it's just the neutral act of letting go of something.

The reading comes from 離れる.