Carefully identify, define each term and give differences between the implementation and the interface of an abstract data type (ADT). This requires a bit more writing of English than other question on this test.

What will be an ideal response?

The interface consists of two sorts of things: commentary, and member function declarations. Commentary is usually at the beginning of the class definition that tells what data an object of the class represents. Typically, this will be something like a date, a bank account, or a person in a company, or the state of a simulation of some kind. In addition to this, the declaration (prototype) of each public member function should have comments that tell you all you need to know about the use of that member function. It is important that the interface of the class give all the necessary information for the use of the class and its members.
The implementation of a class tells how the class interface is realized as code. The implementation includes private members, definitions of both the public member functions and any private member functions. You need the implementation to run a program that uses the ADT.