How is data transferred between the stack and the heap in memory?

In Java, the stack and heap are different memory areas with different purposes. Data transfer between them does not happen directly, but interaction occurs through references and objects:

• Stack stores primitive data types and references to objects.
• Heap is the area where objects are allocated.

When an object is created, it is allocated in the heap, and a reference to this object is stored in the stack. When methods are called and local variables are created, they are placed on the stack.

Example:

public void example() {
    MyObject obj = new MyObject(); // obj is a reference in the stack, the object is in the heap
}

Thus, "moving" is more about passing references from the stack to the heap and back, rather than copying data. Memory management and garbage collection in the heap are handled automatically by the JVM.