Authentication and authorization are two closely-related concepts that are often used in the development of web applications and APIs.

Authentication is the process of verifying the identity of a user or system. This typically involves the user providing credentials, such as a username and password, and the system verifying that the credentials are correct. If the credentials are correct, the user is considered to be authenticated, and they are granted access to the system.

Authorization, on the other hand, is the process of determining what actions a user is allowed to perform within the system. Once a user is authenticated, the system can use their identity to determine what resources they can access and what actions they can perform. This is often done by associating the user with a specific set of permissions or roles, which define what the user can do.

In summary, authentication is about verifying the identity of a user or system, while authorization is about determining what actions the user is allowed to perform. These two processes are typically used together to provide secure access to a system