Authentication means by which communicating entities prove to one another that they are acting on behalf of specific identities that are authorized for access.
Authentication is any process by which you verify that someone is who they claim they are. This usually involves a username and a password, but can include any other method of demonstrating identity, such as a smart card, retina scan, voice recognition, or fingerprints. Authentication is equivalent to showing your drivers license at the ticket counter at the airport.
Authorization (access control for resources).
Authorization means by which interactions with resources are limited to collections of users or programs for the purpose of enforcing integrity, confidentiality, or availability constraints.
Authorization is finding out if the person, once identified, is permitted to have the resource. This is usually determined by finding out if that person is a part of a particular group, if that person has paid admission, or has a particular level of security clearance. Authorization is equivalent to checking the guest list at an exclusive party, or checking for your ticket when you go to the opera.
Data integrity means used to prove that information has not been modified by a third party while in transit.
Confidentiality (Data Privacy).
Confidentiality means used to ensure that information is made available only to users who are authorized to access it.