Cypress is a JavaScript-based end-to-end testing framework built specifically for modern web applications. Unlike traditional testing tools that run outside the browser, Cypress executes in the same run-loop as your application, enabling automatic waiting, real-time reloading, and time-travel debugging. This architecture eliminates flaky tests caused by arbitrary waits, and its interactive Test Runner provides instant visual feedback with DOM snapshots at every command. The framework supports both E2E testing and component testing for React, Vue, Angular, and other frameworks, making it a comprehensive solution for validating user flows, UI components, and API integrations.