The term "garbage collection" is a procedure in the run-time system of a language whereby

erroneous programs are flagged as unexecutable, indicating security risks or need for repair

a heap with no space available to dynamically allocate new objects is made larger so that a program may continue executing

dynamic memory allocated in the heap, but no longer reachable from a program, is returned to the un-allocated heap

rarely called functions are moved to slow memory, making room in fast memory for heavily used functions