C# 0 The Complete Reference

Building

. Thus, 

house

 is a 

variable that can refer to an object, but it is not an object, itself. The next line creates a new 

Building

 object and assigns a reference to it to 

house

. Now, 

house

 is linked with an object.

The fact that class objects are accessed through a reference explains why classes are 

called

reference types.

 The key difference between value types and reference types is what 

a variable of each type means. For a value type variable, the variable, itself, contains the 

value. For example, given

int x;

x = 10;

x

 contains the value 10 because 

x

 is a variable of type 

int

, which is a value type. However, in 

the case of

Building house = new Building();

house

 does not, itself, contain the object. Instead, it contains a reference to the object.