If you, like me, have more of a PHP background and are trying NodeJS. Know that any small error will kill your app and thus your "server" since NodeJS relies on an infinity loop to run itself as a server. There are workarounds to solve this, but none solves it beautifully as PM2. PM2 will ensure that your NodeJS app is running and restart it automatically for you. It has a huge community and therefore documentation. Its features are really impressive.