OAuth 2.0 is a widely-used framework that enables secure delegated access to resources without exposing user credentials by utilizing various grant types, each including core components such as client ID and secret, authorization endpoint, token endpoint, redirect URI, scopes, and access tokens, designed for different applications and use cases, with recommended grant types like the Authorization Code Grant ideal for web and mobile apps with backend servers, and others such as Client Credentials Grant used for server-to-server communication. When implementing OAuth 2.0, it's essential to consider factors like client type, security needs, user experience, and use case mapping to select the best grant type, following best practices such as using HTTPS, setting token expiration times, and securely storing tokens, with a focus on secure authentication and authorization for web apps, APIs, and devices.