In interviews I have been asked to explain the difference between abstraction and encapsulation. My answer has been along the lines of
Abstraction<
ABSTRACTION:"A view of a problem that extracts the essential information relevant to a particular purpose and ignores the remainder of the information."[IEEE, 1983]
ENCAPSULATION: "Encapsulation or equivalently information hiding refers to the practice of including within an object everything it needs, and furthermore doing this in such a way that no other object need ever be aware of this internal structure."