garbage collection

The system by which the Java virtual machine reclaims memory that is no longer being used by the executing Java program. A Java object is eligible for garbage collection when it is set to null, when all references to the object fall out of scope, or when a weak reference to the object exists. Garbage collection is not guaranteed to run during the life of the virtual machine. When an object is garbage-collected, its protected void finalize() method runs, giving the object a chance to clean up after itself.