Native modules in NodeJS context are modules that are written in C/C++ to interact with lower level functions/libraries. Those functions are then wrapped using the NaN, or node-addons-api to make then available in NodeJS.
What Does Require Do
When a module is loaded using the require() function, the module’s code is executed and the exports object of the module is returned. The require() function can be used to load local files as well as modules installed from npm.