The ExpandoObject class refers to a class whose members can be explicitly added and removed at runtime. In other words, the ExpandoObject class allows dynamic binding of the objects, which enables you to use standard syntax, similar to the dynobj.Method method instead of using more complex syntax, such asdynobj.getAttribute("Method").

The DynamicObject class enables you to define the dynamic behavior for an object at run time. This class cannot be instantiated directly; therefore, to implement the dynamic behavior, you must inherit from theDynamicObject class and override the necessary methods. It allows you to define the specific operations that can be performed on dynamic objects as well the methods to perform those operations.

The difference between the var and dynamic data types is that the var data type is strongly type checked at the compile time; whereas, the dynamic data type is type checked by the compiler only at run time. After declaring a var data type, you cannot explicitly change its type throughout the execution of the program; however, a variable of the dynamic data type can be changed during runtime. Another major difference between the two is that dynamic type can also be used as the return type for methods, for which var cannot be used.

The System.Convert class provides a complete set of methods for converting the data types.