OAuth 2.0 is a widely used authorization protocol that enables users to grant third-party applications limited access to their web server resources without sharing private credentials, enhancing data control and security. The protocol distinguishes between authentication, which verifies user identity, and authorization, which determines user privileges. OAuth 2.0 supports various flows, such as the authorization code flow and implicit flow, tailored for different application types and security needs. In a practical scenario, implementing OAuth 2.0 in a React application involves setting up an authorization server and managing authorization flows to authenticate users, often using third-party providers like Google for social logins. The process can be complex and time-consuming, as demonstrated by the detailed steps to configure both backend and frontend components in the article. Alternatively, services like Clerk simplify the process by offering pre-built solutions for user management, authentication, and authorization, allowing developers to focus on core application functionality while ensuring secure access control.