The reference data type in C# does not have the actual data stored in a variable, but they contain a reference to the variables.
In C#, the following are the built-in reference types −
The Object Type is the ultimate base class for all data types in C# Common Type System (CTS). The object types can be assigned values of any other types, value types, reference types, predefined or user-defined types.
object ob; ob = 250; // boxing
Store any type of value in the dynamic data type variable. Type checking for these types of variables takes place at run-time.
dynamic d = 100;
The String Type allows you to assign any string values to a variable. The string type is an alias for the System.String class. It is derived from object type.
String val = "Welcome!";