Google Chrome DevTools is a set of web development tools built directly into the Google Chrome browser. It allows developers to inspect and edit HTML and CSS, debug JavaScript, and analyze website performance. With features like the Elements panel, Console, and Network tab, users can gain insights into how their web pages function and identify issues. DevTools also provides tools for mobile device simulation, allowing developers to test how their sites appear on different screen sizes. Additionally, it includes a Performance panel to monitor loading times and resource usage, helping optimize web applications for better user experiences.