Authorization is the process of determining a user’s or system’s permissions after their identity has already been verified through authentication. It answers the question: “What are you allowed to do in the system?”
In simple terms, authentication confirms who you are, while authorization defines your level of access to system resources, data, and functions. These two processes always work together and form the foundation of any access control system.
Authorization is used in web applications, enterprise systems, cloud infrastructure, APIs, and any services with role-based access control.
How Authorization Works
After successful authentication, the system retrieves user information and determines access rights. These permissions are typically defined in advance using roles, policies, or individual rules.
For example, in an enterprise system, an employee may be able to log in, but access to financial data is restricted based on their role. The system evaluates permissions and decides whether to allow access to a specific resource or action.
Authorization is commonly implemented using:
- Role-Based Access Control (RBAC)
- Attribute-Based Access Control (ABAC)
- Policy-Based Access Control
Key Principles of Authorization
Authorization is based on a set of access control rules and logic:
- Access is granted only after authentication
- Permissions depend on user roles or context
- Access can be restricted by resource, action, or time
- The system enforces the principle of least privilege
For example, an API user may be allowed only to read data but not to modify or delete it.
Where Authorization Is Used
Authorization is used in all systems where user actions must be controlled:
- Web applications and SaaS platforms
- Enterprise IT systems and ERP solutions
- Cloud services and infrastructure
- APIs and integration platforms
- Identity and access management systems
For example, in a cloud platform, one user may be allowed to create virtual machines, while another can only view their status.
Authentication vs Authorization
Authorization is often confused with authentication, but they are different processes:
- Authentication verifies a user’s identity
- Authorization defines what the user is allowed to do
Both processes work sequentially: first login, then permission evaluation.