What is abstraction? As manifest in computer science, abstraction is th epurposeful suppression, or hiding, of some details of a process or artifact, in order to bring out more clearly other aspects, details, or structure. In abstraction we try to uncover the inherient characteristics of an item, ignoring unnecessary details.
For example, I might abstract my view of an automobile by saying it is a device that connects fuel to an engine, a transmission, and the wheels. At the high level this has some relationship to reality, and it allows me to break the system down into component parts, examining those parts in isolation from each other.