Abstract Data Types ( ADT )

Very often we just want to go with the visionary imaginary effect of the data structure without having worries about the implementation attributes or how the data is being stored and accessed. We can employ this by formulating mathematical abstract models of particular classes of different data structures or data types that have certain features required for our implementation.

Abstract Data Types are data types together with the operations, whose properties are specified independently of any particular implementation. To simplify the process of solving problems, We combine the data structures with their operations and call them ADTs.Consists of two parts:

• declaration of data.
• declaration of the operations. 

Thus, the notion of the data structure in the abstract needs to be treated differently from whatever it is used to implement the data structure the abstract notion of a data structure is defined in terms of the operation we plan to perform on the data.

Also the design of a data structure involves more than just its organization you also need to plan the way the data will process and to be accessed that is how data will be interpreted in a non-contagious structure like lists trees or graph or likewise in the structure that are normally treated as contiguously such as arrays.

An abstract data type in a theoretical construct that consists of data as well as the operations to be performed on the data while hiding implementation attributes, as an application of data encapsulation.

To be made useful, an abstract data type (such as stack) has to be implemented and this is where data structure comes into play. For instance, we might choose the simple data structure of an array to represent the stack, and then define the appropriate indexing operations to perform pushing and popping operations.

As another example, the code to read from a keyboard is an ADT. It has a data structure, character, and set of operations that can be used to read that data structure.