what are public and private functions??

Answer 1

Public and private are access specifiers for a class. Public members can be accessed anywhere in the program through the use of an object. Private members can only be accessed from other members inside the class.

To answer your question, the term "members" applies to functions too.

Answer 2

Extending on Cohen's answer, classes can be made 'friends' of one another. Classes that are friendly with one another can access the private members of one another's classes as well as the public members.