Difference between byval and byref in net?

we can pass parameter in procedure and function two type one is Byval and other is byRef, in byval value Store in stack And byref store in Heap. in a Byval get value a predefind and userdefind by replica and copy of the value. but in byRef program access address of the Variable we can pass parameter in procedure and function two type one is Byval and other is byRef, in byval value Store in stack And byref store in Heap. in a Byval get value a predefind and userdefind by replica and copy of the value. but in byRef program access address of the Variable