node.js - What's the difference between engine.io and socket.io?

Question

Please correct me if this question is a duplicate. Regarding node.js, I'm using socket.io for real-time socket connection from the client application to the server application. I just heard about engine.io, is engine.io a replacement for socket.io? I could not find any useful information on engine.io website

Thanks in advance

Answer 1

engine.io is a lower level library than socket.io.

Engine is to Socket.IO what Connect is to Express.

If you want the lower level abstraction, use engine.io. If you want a websocket abstraction, keep using socket.io.

engine.io is of more interest to you if you're building a library/framework on top of socket.io.

socket.io is of more interest to you if you're building an application on top of socket.io.