Comment by iceboundrock

Primitive variables in Java, such as `int`, `boolean`, and `double`, store their actual values directly in memory. When they are local variables inside a method, this memory is typically allocated on the thread's stack. These primitives do not have the structure or overhead of an object, including the object header used by the Garbage Collector (GC) to manage heap-allocated objects.

If a primitive value must be treated as an object (e.g., when stored in a Java Collection like ArrayList or when passed to a method that requires an object), Java uses a process called `boxing` to wrap the primitive value into an instance of its corresponding Wrapper class (e.g., Integer, Boolean, Double). These Wrapper objects are allocated on the heap and do possess the necessary object header, making them subject to the GC's management.