What is the process object in Node.js?

Direct answer

process is a global Node object representing the running Node process — it exposes env vars, argv, cwd, exit codes, stdin/stdout/stderr, and lifecycle events like beforeExit and signal handlers for graceful shutdown.

Every Node program has exactly one process instance. Servers read PORT from process.env; CLIs parse process.argv; production apps listen for SIGTERM to drain connections (Q73).

Property / method	Purpose
process.env	Environment variables (strings)
process.argv	CLI args — [node, script, ...flags]
process.cwd()	Current working directory
process.exit(code)	Terminate process — 0 success, non-zero error
process.pid	OS process ID
process.on('SIGTERM')	Graceful shutdown hook in containers

stdin / stdout / stderr — streams for CLI tools and piping: node script.js | grep foo.
process.version — Node semver string; pair with process.versions.v8 (Q12).
uncaughtException — last-resort handler; prefer fixing errors, not relying on it (Q63).

process-basics.mjs

const port = Number(process.env.PORT) || 4000;
const isProd = process.env.NODE_ENV === "production";

console.log("Node", process.version, "pid", process.pid);
console.log("Args:", process.argv.slice(2));

process.on("SIGTERM", () => {
  console.log("Shutting down gracefully…");
  server.close(() => process.exit(0));
});