How does the Garbage collector works?

Question

I understand that GC is a means to take care of memory, but what is it, as it is called and specifically what it does?

Answer 1

It is nondeterministic in sense of when is it called, the framework does that every so often, you cannot really trigger it.
Garbage collector pretty much goes through allocated memory and deletes (frees) every object which does not have a valid reference to it (unreachable).