Authentication and Authorization has very simple definitions. Authentication means proving that something is real like showing authenticity of rare coins. Authorization means giving somebody consent to take an action or use something. But what is the technological definition of authentication and authorization?

Authentication

Authentication in technology terms means proving user, are actually who you claim to be. It's a verification of identity. As a user, providing authentication by supplying an application, network or site with particular credentials allocated to you. In many cases, these credentials involve a user name and a password. Sometimes they may add Social Security number or employer- ID number.
Authorization

Authorization is a procedure that grants right or denies use of resources. If allowed to use a service, then you have authorization. If network administrator has set access controls to allow, you can use files, services, printers and other resources shared on network.
Uses of Authentication

Authentication technologies are used to make sure that you are a human being and not a program. Websites often do this through "captcha". A captcha needs entering generated code to gain access or submit a form.
Uses of Authorization

Authorization is a security gauge used in network made to avoid users from gaining data, files or resources beyond their security clearance. It even prevents outsiders from gaining access to network. All users on a network are allocated an IP address created for their workstation. If a PC attempts accessing network from an address not connected to authorize users, access is denied.
How They Work Together

Authentication and authorization work hand in hand in a network. First, you are authenticated by entering user name and password. After logging in, network decides what permissions have been granted you to open files or use services based on authorization.