...This utility inspects the active handles and resources in the runtime, prints a breakdown of open callbacks, sockets, timers, and other tasks, and explains what’s keeping Node running, helping you track down leaks or unintended resource retention. It’s particularly useful during testing, when you expect Node to exit after tests finish, or in long-running servers when you're debugging resource leaks or shutdown logic. By providing clear human-readable output that lists current handles and their origins, the tool dramatically reduces the time you would otherwise spend manually instrumenting your code.