Reference counting is garbage collection. I mention this because the site claims no GC nut you claim I'm this thread that ref counting is sometimes used, which makes sense because borrowing sometimes isn't enough.
While reference counting is technically a method of collecting garbage, in modern parlance the phrase "garbage collector" is mainly used for systems capable of collecting garbage of an arbitrary reference graphs, which reference counting by itself cannot do (cyclic references).
PL circles: reference counting is also “garbage collection”