TIL30 - JS - Packages vs. Modules

What is the difference between a package and a module in JavaScript?

In short, the key difference is that a package includes a package.json file, but a module doesn't have to have it.
In common practice, a package is regarded as a collection of modules, and a module as a single file.

> Official npm definition (docs.npmjs.com):

• Package: a file or directory that is described by a package.json file. A package must contain a package.json file in order to be published to the npm registry.
  A package is any of the following:
  - A folder containing a program described by a package.json file.
  - A gzipped tarball containing (a).
  - A URL that resolves to (b).
  - A <name>@<version> that is published on the registry with (c).
  - A <name>@<tag> that points to (d).
  - A <name> that has a latest tag satisfying (e).
  - A git url that, when cloned, results in (a).
  
• Module: any file or directory in the node_modules directory that can be loaded by the Node.js require() function.
  To be loaded by the Node.js require() function, a module must be one of the following:
  - A folder with a package.json file containing a "main" field.
  - A folder with an index.js file in it.
  - A JavaScript file.
  

| Note: Since modules are not required to have a package.json file, not all modules are packages. Only modules that have a package.json file are also packages.