Authentication and authorization are two related concepts in computer security that are often used together to control access to resources and services. However, they are distinct concepts with different purposes and functions.
Authentication is the process of verifying the identity of a user, device, or system. This typically involves presenting some form of credentials, such as a username and password, a digital certificate, or a biometric identifier, and verifying that the credentials are valid and belong to the entity that is trying to access the resource. Authentication is typically used to determine whether a user or device is who or what they claim to be, and it is an important step in ensuring the security and integrity of a system.
Authorization, on the other hand, is the process of granting or denying access to a resource or service based on the identity and permissions of the user or device that is requesting access. After the identity of the user or device has been authenticated, the authorization process determines what actions the user or device is allowed to perform on the resource or service, and what information or data they are allowed to access. This is typically done by checking the user or device's permissions or privileges, which specify what actions and resources they are allowed to access.
In summary, authentication is the process of verifying the identity of a user or device, while authorization is the process of granting or denying access to a resource or service based on the user or device's identity and permissions. Both authentication and authorization are important for maintaining the security and integrity of a system, and they are typically used together to control access to resources and services.