What happens when you switch ON the monitor or when any call is received by you on your phone? Does it really matter to you
what is happening inside these devices? No, it does not. Right? Important thing for you is whether these devices are working as per your requirement or not? You are never concerned about their inner circuitry. This is what we call abstraction.
The process of identifying and separating the essential features without including the internal details is abstraction. Only the essential information is provided to the outside world while the background details are hidden. Classes use the concept of abstraction. A class encapsulates the relevant data and functions that operate on data by hiding the complex implementation details from the user. The user needs to focus on what a class does rather than how it does.