Access specifiers in C++ class define the access control rules. C++ has 3 new keywords introduced, namely,
public private protected
These access specifiers are used to set boundaries for availability of members of class be it data members or member functions
Access specifiers in the program, are followed by a colon. You can use either one, two or all 3 specifiers in the same class to set different boundaries for different class members. They change the boundary for all the declarations that follow them.