How the Heck Does OAuth Work?

OAuth is an open standard protocol used for secure authorization, allowing websites and applications to access user information without exposing passwords. Since its inception, OAuth has evolved from the complex OAuth 1.0 to the more streamlined and flexible OAuth 2.0, which introduced access and refresh tokens and supports multiple grant types. Key OAuth flows, such as Authorization Code Grant, Implicit Grant, Resource Owner Password Credentials Grant, Client Credentials Grant, and Device Code Grant, cater to various application needs from web to client-side and server-to-server communications. OAuth is prominently used in scenarios like Single Sign-On (SSO) and granting third-party applications access to user data, enhancing security and user experience. Understanding these flows and their applications is essential for developers working with modern web and mobile applications.