Type compatibility

Question: In spite of the difference between value types and reference types all .NET types are compatible with System.Object. How is this compatibility achieved for value types?

Answer: see 3.2.4 From Value Type to Reference Type and Back

This compatibility is achieved through a mechanisms known as "Boxing":
Objects of values types are copied into structure equivalent reference type objects on the heap and a reference to the result is stored in the reference type variable.
Such "boxed" value type objects can then be reassigned to value type variable and thus copied to the stack.