What does the grunt nodejs npm relationship look like?

I fiddled with grunt yesterday, but I didn’t quite understand it at the beginning. Now it seems to have a vague concept. I don’t know if it’s right or not. I hope to get some pointers. ?
Why does installing grunt require nodejs first?
Because grunt needs npm package manager.
why nodejs?
Because the development of nodejs involves module development, many third-party plug-ins or modules are used, which is convenient for downloading, so when downloading nodejs, npm is directly downloaded and installed together.
what is npm?
A package management program that can connect to the npm server through the command line and download the required plugins for installation.
what is grunt?
Because the download of npm plugins is mentioned above, it is definitely necessary to apply several downloaded plugins to actual production. How to apply? Just through grunt.
Grunt can automate the execution of npm plugins installed on your computer through the settings of certain configuration files (package.json&Gruntfile.js). From checking to merging to compressing and more, a series of operations
only requires you to move your finger, because it is five times (type the command grunt).