Webpack is a code bundler. It takes the files in your code, transforms them, and gives you a new version of your code that can be interpreted by the browser.
SASS/LESS => CSS
CoffeeScript => JavaScript.
Webpack just needs to know..
- where your application starts (Usually index.js or your root JS file.)
- what transformations need to be done to your code
- where your bundle gets created to display to the browser