Value type and reference type
In computer programming, data types can be divided into two categories: value types and reference types. A value of value type is the actual value. A value of reference type is a reference to another value.Programming languages that distinguish between value types and reference types typically offer a mechanism, called boxing, to wrap some or all of their value types in reference types. This permits the use of value types in contexts expecting reference types. The converse process is known as unboxing.
