What is Abstraction ? (In object oriented technology)

Abstraction refers to the act of representing essential features without including the background details or explanations. Classes use the concept of abstraction and are defined as a list of abstract attributes such as size, weight and cost, and function to operate on these attributes. They encapsulate all the essential properties of the objects that are to be created The attributes are sometimes called data members, because they hold information. The functions that operate on these data are sometimes called methods or member functions. Since the classes use the concept of data abstraction, they are known as use Abstract Data Types (ADT).
The of deciding what parts of a real world object are essential to process modeling the solution to a paricular problem is called abstaction. Abstraction is the representation of all the essential features of an object which means its possible states and behaviours. These are 'encapsulated' into an "abstract data type" which define how all objects in class (type) of object are to be represented and how they behave.
Abstraction is mechanism that enables the designer to focus on the a essential details of a program component with little concern for lower-level detail. Abstraction is a relative concept. As we move to higher levels of abstraction we ignore more and more details,  I.e. we give a more general look of a concept or item.