What is node.js
It is used to develop I/O intensive web applications mostly angular JS application.
Node.js is open source, completely free.
What is npm [Node package manager]
npm is an online repository for the publishing of open-source Node.js projects.
Note : npm is distributed with Node.js– which means that when you download Node.js, you automatically get npm installed on your computer.
Navigate to https://nodejs.org/en/download/ [download specific to your platform]
Verify if node.js / npm is installed?
in Windows OS – Open command prompt
in Mac OS – Open terminal
As a result output, you will get the version of nodejs or npm command.