Webpack is an open-source tool for bundling, packing, and processing, javascript files. I’ve used it extensively on most JS projects I’ve been part of since 2016, and it’s been a very nice experience compared to it’s predecessors Gulp and Grunt.
Alternatives
Lately, a bunch of contendors have started to gain some momentum, primarilly Rollup and Parcel, but in all the projects I’ve tried them so far, I’ve ultimately ended up switching back to Webpack for various reasons.