I'm getting my hands dirty with Babel for the 1st time to convert Jest tests from ES6 syntax to commonJS; this will likely involve using the @babel/plugin-transform-modules-commonjs babel plugin which I'm trying to install in my Next.js project. Looking at this part of Babel's configuration docs, I see the term package pop up a lot.
Are package hierarchies a Babel convention, Node-defined feature, or part of base JavaScript itself? What exactly defines a package in this context, and where is there documentation for them? Is babel-jest a stable alternative to this problem?