cjs
cjs stands for CommonJS. It is a module system for JavaScript that was popularized by NodeJS, and as such typically used in server-side JavaScript.
CommonJS uses the require keyword to import modules:
Javascript
const fs = require('fs')
In recent years, cjs is increasingly being replaced by esm, or ECMA Script Modules which is the official module system of the JavaScript language, and the future-proof choice.
Since version 3, FreeSewing is ESM-only.