What is Data Encapsulation in Object-oriented programming?

The wrapping up of data and function into a single unit (called class) is known as
encapsulation. Data and encapsulation is the most striking feature of a class. The data is
not accessible to the outside world, and only those functions which are wrapped in the
class can access it. These functions provide the interface between the object’s data and
the program. This insulation of the data from direct access by the program is called data
hiding or information hiding.