Tell me about NPM: what it is and what it is used for.

NPM (Node Package Manager) is a package manager for JavaScript that allows you to install, update, and manage libraries and dependencies in your projects. It is used to simplify working with external modules that can be integrated into your application without writing all the code from scratch.

Main tasks of NPM:

• Managing project dependencies (installing, updating, removing packages).
• Storing and publishing your own packages.
• Automating tasks through scripts.

Example of installing a package:

npm install lodash

After that, you can use the library in your code:

const _ = require('lodash');
console.log(_.shuffle([1, 2, 3, 4]));