Amazon Cognito is a user identity and data synchronization service provided by AWS that helps manage user authentication and authorization for web and mobile applications. It includes user pools for user directories, identity pools for temporary AWS credentials, and features for user sign-up, sign-in, social sign-in, multi-factor authentication, data synchronization, and user management. An example scenario describes a company using these Amazon Cognito features to build a mobile app for customers to order products and track deliveries.