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Authentication and Authorization

What is the Difference Between Authentication and Authorization?

Security authentication and authorization both play important roles in online security systems. The terms are often used interchangeably, but they are quite different.


Authentication is the process of confirming a user’s identity in order to provide access to sensitive information. This is often accomplished via username and password. The website authentication process works by comparing the user’s credentials with the credentials that the system has on file. If the credentials match, the authentication process is complete, and the user will be permitted to proceed. A system can use many different elements and combinations of elements for authorization:

Single-factor authentication. This is the simplest form of authentication. It requires only one credential to verify one’s identity, such as a password.

Two-factor authentication. This form of authentication requires an additional credential beyond the username and password, such as a piece of information that only the user knows.

Multi-factor authentication. This is a more advanced form of security which requires two or more levels of security from independent categories of authentication. This form of authentication is often used for organizations with highly sensitive data such as financial organizations, banks, and law enforcement.

Biometric authentication. This method includes any method that requires a user’s biological characteristics to verify their identity. Some examples of biometric authentication include facial recognition tools and fingerprint scanners.


Authorization occurs after your identity has been successfully authenticated by the system. Once the system has verified a user’s identity, it determines what that user is able to do and see on a website; these are called permissions. Authorization could give a user permission to access specific parts of a website, or it could give a user full access to all resources such as databases, files, funds, etc. Permissions are essential because they prevent users from accessing accounts that are not theirs, they restrict free accounts from accessing premium features, and they ensure internal accounts only have access to what is relevant to them. Authorization methods include access controls for URLs, secure objects and methods, and access control lists (ACLs).

An easy way to understand the relationship between authentication and authorization is that authentication asks, “Who are you?” and authorization asks, “What are you allowed to do?” Authentication and authorization work together; authentication identifies users while authorization determines their permissions. These functions are especially critical for websites or applications that process online transactions or personal information, as these steps will prevent unauthorized users from accessing accounts without permission, keeping sensitive personal data secure.