For example, control abstraction in structured programming 
is the use of ... Object-oriented programming can be seen 
as an attempt to abstract both data and

Abstraction is thing which you directly not use.
like as in motor making all spare aprart are come from 
differnt class which all are combined in one motor class 
where we use it.
we direclty not use any only one think as tyre or petrol
for use it we want to combine that all.

Hiding own nessesary data from the user it is called 
Abstraction

Abstraction refers to the attributes of an object that 
clearly demarcates it from other objects.

Abstraction is basically the data types,information 
associated with a function,object which may not be required 
by user therefore that unnecessary data is hidden from user.
e.g. int a,  only data type nature is provided not about 
its memory space.

data abstraction means hiding the unneccessary part
Data abstraction is main feature of c++