The User Defined data type are the type in which we can defined such data type according to our requirement. Some example of user defined data type are Enumeration and Structure Type. Â Today we will discuss the user defined Data Types. In this article we will learn how to declare and define enumeration data type and structure data type. Also we will see that how we can access/ retrieve the values that are stored in these User defined Types. I hope that this will help you to learn something about Enumeration and Structure Type.