What are the JavaScript libraries and how many of them?

Answer 1

Jquery is one of them. The other libraries include;
- Node.js
- P5.js
- three.js
- React.js

Using libraries can help you to create better codes

Answer 2

Node isnt a library, its a js based server environment :)

But to answer the second question:
There are probably more then 300000 of different librarys. The reason for that is, that every person can build his own library fairly easy (basically not just in js ;))