You have access privileges in C++ such as public, protected and private that helps in
encapsulation of data at various level.

Private
If data are declared as private in a class then it is accessible by the member functions of the class
where they are declared. The private member functions can be accessed only by the members of
the class. By default, any member of the class is considered as private by the C++ compiler, if no
specifier is declared for the member.

Public
The member functions with public access specifier can be accessed outside of the class. This
kind of members is accessed by creating instance of the class.

Protected
Protected members are accessible by the class itself and it’s sub-classes. The members with
protected specifier act exactly like private as long as they are referenced within the class or from
the instance of the class. This specifier specially used when you need to use inheritance facility of
C++. The protected members become private of a child class in case of private inheritance, public
in case of public inheritance, and stay protected in case of protected inheritance.