Before you bury yourself in packages, learn the Node.js runtime itself: Answers-Part3

11. What Node module is implemented by most other Node modules?

This is just an example of a single module called ‘events’ which is implemented by other modules in NodeJS. For eg. EventEmitter of events module is used by ReadableStreams, WriteablStreams and so on.

Commonly used NodeJS modules are events, buffer, util, stream. You can find several common modules used by other modules form nodejs github repository.