Understand the difference between authentication and authorization.
Authentication and Authorization are two fundamental pillars of database security, often used together but representing distinct concepts. Authentication is the process of verifying who a user is. It's the first step in any security system. The most common form of authentication is a username and password combination. When a user tries to connect to the database, they provide their credentials, and the DBMS checks if they match a registered user account. If they match, the user is authenticated, and a connection is established. Other, more secure methods of authentication exist, such as using security certificates, biometric data, or multi-factor authentication. Authentication answers the question: 'Are you who you say you are?'. Once a user's identity has been confirmed through authentication, the next step is Authorization. Authorization is the process of determining what an authenticated user is allowed to do. It deals with permissions and access rights. A user might be authenticated to access the database, but they might only be authorized to perform certain actions. For example, a data analyst user might be authorized to `SELECT` data from the 'sales' table but not to `UPDATE` or `DELETE` records. A clerk might be authorized to `INSERT` new records into the 'orders' table but not to view the 'employees' table. In SQL, authorization is managed by the database administrator (DBA) using Data Control Language (DCL) commands, primarily `GRANT` and `REVOKE`. Authorization answers the question: 'Are you allowed to do that?'.