The JVM Garbage Collector is in support of the whole object's life cycle management the JVM provides. Whenever you see the word new in Java code, memory is allocated in a JVM memory segment called heap.
Java completely takes care of memory management and it is impossible to overwrite memory segments that do not belong to you (or your object). So if you write something to an object's memory segment on the heap (for example by updating a class property value of type Integer, you are changing 32 bit on the heap) you don't use the actual heap memory address for doing so but you use the reference to the object and either access the object's property or use a setter method.
So we've learned about new allocated memory on the heap, but how does it ever get freed? This is where the Java Garbage...