Authentication:
Authentication is the process of verifying the identity of a user or entity. It ensures that the user or entity is who they claim to be. Authentication is typically performed by presenting credentials, such as a username and password, to a system or application. The system then verifies these credentials against a stored record to authenticate the user's identity. Other authentication methods include biometric authentication (e.g., fingerprint or facial recognition) or using digital certificates.
Authorization:
Authorization, on the other hand, is the process of granting or denying access rights and permissions to authenticated users or entities. Once a user's identity is authenticated, authorization determines what actions or resources the user is allowed to access. Authorization is typically based on predefined rules or policies that specify what permissions or privileges are associated with different user roles or levels of access.
In summary, authorization answers the question, "What are you allowed to do?" and controls the user's access to specific resources or actions within a system or application.
To illustrate the difference, think of a scenario where you enter a building (authentication) by scanning your ID card at the entrance. Once inside, your access is further controlled by different levels of authorization. For example, you may have access to certain floors or rooms based on your job role or security clearance.