What are Value type and reference types and Reference types

Value types directly contain their data that either allocated on the stack or allocated in-line in a structure. So value types are actual data.

Reference type store a reference to the value's memory address, and are allocated on the heap. Reference type can be self-describing types, pointer types, or interface types.

Variable that are value types each each have their own copy of the data, and therefore operation on one variable do not effect other variables. Variables that are reference types can refere to the same object. Therefore,operations on one variable can effect the same object referred to by another variable. All types derive from the System.Object base type.