Puppeteer is a Node.js library that provides a high-level API to control headless or full browser versions of Google Chrome or Chromium. It simplifies browser automation, making it an excellent choice for tasks such as automated testing, web scraping, and capturing screenshots. Puppeteer operates in a headless mode by default, meaning it runs without a visible UI, but can also be configured to control a full browser for more visual debugging. Its flexibility and power make it an essential tool for developers needing reliable browser automation.