Handling process signals is essential for building robust Node.js applications that can respond appropriately to system-level interruptions. Signals are notifications sent to a process by the operating system or another process, often to inform it of external events. The most common signals you will encounter are SIGINT and SIGTERM.

SIGINT is typically sent when you press Ctrl+C in the terminal. It is used to indicate that a user wishes to interrupt the process. SIGTERM is a termination signal that allows the process to perform cleanup before shutting down; it is often used by system tools or service managers to request a graceful shutdown.

When your application receives these signals, you should use the process.on() method to register handlers that perform necessary cleanup tasks. These might include closing database connections, saving state, or releasing resources. Failing to handle signals can result in data loss, resource leaks, or an unresponsive system. It is a best practice to always ensure that your application can shut down cleanly by listening for signals and exiting gracefully after cleanup is complete.