I am a noob here, so maybe this is obvious, but how exactly is a "lock" defined? it seems to me the acquire/release semantics are very similar to locks? I.e. I'

I am a noob here, so maybe this is obvious, but how exactly is a "lock" defined? it seems to me the acquire/release semantics are very similar to locks? I.e. I'm struggling to understand what is "lockless" about the primitives.