Auth: Difference Between Authentication and Authorization.

In web development, authentication and authorization are two critical concepts that govern access to resources and functionalities in a system, but they address different aspects of security.

1. Authentication

Authentication is the process of verifying the identity of a user. It ensures that the person or entity attempting to access a system is who they claim to be. Authentication often involves:

• Username and password: The most common form of authentication, where a user enters credentials that are validated against stored data.

• Multi-factor authentication (MFA): Adds an additional layer of security by requiring a second form of identification (e.g., a code sent via SMS or generated by an app).

• Biometrics: Authentication methods using fingerprint scans, facial recognition, or other physical attributes.

• OAuth / Social login: Allowing users to authenticate using external services (e.g., Google, Facebook, GitHub).

Once authenticated, a system knows who the user is. Authentication is concerned solely with confirming identity, but it does not define what the user is allowed to do in the system.

2. Authorization

Authorization occurs after authentication and determines what actions or resources the authenticated user has permission to access. It's essentially about defining what a user can and cannot do:

• Role-based access control (RBAC): Users are assigned roles (like admin, editor, user), and each role has specific permissions.

• Attribute-based access control (ABAC): Access is granted based on attributes like user identity, resource type, or time of access.

• Permission-based access control: Fine-grained control where individual permissions are assigned to users directly, allowing them to perform specific actions.

For example, after authentication, an admin user may be authorized to view and modify all user data, while a regular user can only view and modify their own profile.

Summary:

• Authentication: Verifies the user's identity.

• Authorization: Defines the user's privileges and access to resources.

In web applications, these concepts are often implemented together, such as:

• JWT (JSON Web Tokens) or Session-based Authentication: For authentication.

• Middleware or ACLs (Access Control Lists): For authorization.

In frameworks like Laravel, you might use Auth::attempt() for authentication and Gate::allows() or middleware for authorization checks.