What is an abstraction ? Can there be multiple abstractions of a real-world entity ?

Abstraction refers to the act of representing essential features without including the back­ ground details or explanations.

Yes, there can be be multiple abstractions of a real-world entity because abstraction is always relative to the purpose or user.

For instance, if we consider a student, we can talk of anything that belongs to her in the real world like her name, family, parents' profession, locality she lives in, marks obtained by her, her roll-number in the class, her medical history, her talents, her awards etc. But when we talk of a student result tracking system, the abstraction for it would be her roll-no, name, marks obtained etc. For extra-curricular activities, the abstraction would be her roll-no, talents and awards.