Authentication is the process of obtaining information from users and evaluating their authenticity. Authorization is the process of allowing access to authenticated resources. The permission is as follows: Authentication and authorization may be accomplished in a variety of methods. For example, users can be granted several types of access to the program, including READ ONLY access, Write Access, Delete Access, and so on. Authentication is an issue for both IT system architects and developers. Applications that hold sensitive data must be protected from malicious attacks and rivals seeking to steal information or intellectual property.  When developing a security model for the application, we should consider the business requirements for authentication as well as the influence that security model selection may have on performance, scalability, and deployment.  Authentication can be classified into several types:  Basic Authentication  Passport Authentication  Windows Authentication  Digest Authentication  Form Authentication  Anonymous Authentication  Port Authentication  Using Cookies   Certificate Authentication