Unlike Selenium, which operates outside the browser and communicates via remote commands, Cypress runs directly inside the browser, providing deeper integration and control over the application under test .
Traditional Tools (Selenium/WebDriver): These run outside the browser. Your test script sends commands (via a JSON wire protocol or WebDriver BiDi) to a driver, which then communicates with the browser. This adds network latency and a 'middleman' layer.
Cypress: It runs inside the browser. Because Cypress is executed in the same run-loop as your application, it has native access to every object—the window, the document, the DOM elements, and even your application's state.
Automatic Waiting: Cypress automatically waits for commands and assertions before moving on. It monitors the DOM and 'retries' until the element appears or a timeout is reached
No 'Sleeps': You almost never need to hardcode sleep() or wait() commands in Cypress, which significantly reduces flaky tests.
In other tools you get a log file and maybe a screenshot of the failure. In Cypress you can hover over commands to see the exact state of the UI at that moment.
While other tools provided static screenshots, In Cypress you get full DOM snapshots that you can inspect with DevTools.
Other tools requires driver (geckodriver, chromedriver) and dependencies but for cypress one npm install and you are ready to go.