PM2 is a popular process manager for Node.js applications. It helps developers manage and keep their applications running smoothly by providing features like automatic restarts, load balancing, and monitoring. PM2 simplifies the deployment process and allows for easy management of multiple applications on a server. One of the key features of PM2 is its ability to run applications in the background, ensuring they remain active even after a server reboot. It also offers a web-based dashboard for real-time monitoring, making it easier to track performance and resource usage. This tool is widely used in the Node.js community for its efficiency and reliability.