webpack is a static module bundler for modern JavaScript applications. Starting from one or more entry points it builds a dependency graph of every module and asset a project imports, then emits optimized bundles that browsers can load, handling not only scripts but also stylesheets, images, fonts and HTML through its loader system.
The official site documents concepts such as entry, output, loaders, plugins, mode and browser compatibility, plus guides for code splitting, tree shaking, caching, lazy loading, asset modules, hot module replacement and production optimization, along with a full configuration reference, migration notes and a plugin API.
It suits teams maintaining large single-page applications with many asset types, projects that need fine-grained control over chunking and caching, legacy codebases that must support older browsers, and engineers who need to integrate custom build steps into an established toolchain.
Compared with newer native-speed bundlers it offers a far larger plugin ecosystem and more explicit configuration at the cost of setup complexity and slower cold builds; compared with simple script concatenation it adds dependency resolution, hashing and splitting, though small projects may find a zero-configuration tool sufficient.
Pin the webpack and loader versions in the lockfile, keep production and development configurations separate, use the official bundle analyzer before tuning split chunks, and read migration notes carefully because defaults and plugin APIs have changed noticeably between major versions.