garbage collection
form of automatic memory management
reference counting
sorftware resource tracking technique
Concurrent Mark Sweep collector
mark-sweep garbage collector in the Oracle HotSpot Java virtual machine
mark-compact algorithm
garbage collection algorithm based on the mark-sweep algorithm and Cheney's copying algorithm: reachable objects are marked, then marked objects are relocated toward the beginning of the heap
tracing garbage collection
automatic memory management that traces which objects are reachable by a chain of references from root objects and deallocates the rest