Description of public, private, protected

I saw the professor's PPT that distinguished the types of methods in the class diagram public - Access control to disclose one's attributes or actions to the outside world Private-Access control accessible only to inherited derived classes Access control that can only access the member functions of the protected-structure and cannot be accessed from the outside

It says so. But I wanted to distinguish between private and protected I tried googling, but I think the explanation between private and protected has changed... Is there anyone who is sure?