Webpack is an open-source JavaScript module bundler. It is made primarily for JavaScript, but it can transform front-end assets like HTML, CSS, and images if the corresponding loaders are included. webpack takes modules with dependencies and generates static assets representing those modules.

Webpack takes the dependencies and generates a dependency graph allowing web developers to use a modular approach for their web application development purposes. It can be used from the command line, or can be configured using a config file which is named webpack.config.js. This file is used to define rules, plugins, etc., for a project. (Webpack is highly extensible via rules which allow developers to write custom tasks that they want to perform when bundling files together.)