Authorization<\/a> is a critical security process that determines whether a Client<\/a> or User<\/a> has the necessary permissions to access a specific resource or perform an action within an API<\/a>. While Authentication<\/a> verifies identity, authorization focuses on the scope of access granted to that identity. In modern distributed systems, this is often managed through centralized Identity Providers<\/a>.<\/p> The industry standard for delegating API Security<\/a> is OAuth 2.0<\/a>, which utilizes Access Tokens<\/a> to communicate permissions. These tokens often take the form of JSON Web Tokens (JWT)<\/a>, which contain claims about the user's Scopes<\/a> and roles. Detailed specifications for these protocols can be found at the Official OAuth Website<\/a> and within IETF RFC 6749<\/a>.<\/p> Common methodologies for implementing authorization include Role-Based Access Control (RBAC)<\/a>, where permissions are tied to defined roles, and Attribute-Based Access Control (ABAC)<\/a>, which offers more granular control by evaluating attributes of the user, resource, and environment. Effective authorization prevents vulnerabilities such as Broken Object Level Authorization (BOLA)<\/a>, a frequent entry on the OWASP API Security Top 10<\/a>.<\/p>