webpack: The Standard Tool for Frontend Engineers Worldwide

webpack is a module bundler for JavaScript applications that runs on Node.js—a JavaScript runtime used on computers and servers outside of the browser environment. As a module bundler that supports both ESM and CommonJS, it analyzes the dependencies within an application and bundles them into one or more packages.

The role of the frontend is expanding every day, and with it, the proportion of code it occupies is increasing. If all of this code were crammed into a single file, the file size would become enormous. If users were forced to load such a file upon their first access, they would be left waiting indefinitely for a single file containing even irrelevant code, leading to significant stress.

To solve this, webpack combines multiple JavaScript files into a single file and outputs it to be sent from the server to the browser.

Writing lengthy processes in a single JavaScript file leads to poor readability. This can be addressed by splitting the code into multiple files. In the web-centric frontend community, these split JavaScript files are called "modules."

Since JavaScript modules cannot be used as-is in legacy browsers or Internet Explorer 11, webpack allows you to convert these modules into a format that browsers can handle. Furthermore, it automatically combines them while taking the dependencies between multiple files into account.

While automatic merging is already convenient, webpack can bundle more than just JavaScript—it can also handle stylesheets and images. This is a significant benefit that leads to the optimization of data transfer mentioned earlier.

Various assets can be bundled (aggregated) into JavaScript files.

What did you think of this overview? Beyond the features introduced here, webpack also functions as a comprehensive production environment, capable of compressing JS, optimizing images, and even launching local development servers. While it may take some time to master, introducing webpack provides the essential technology and development environment required for a frontend engineer. Please take this opportunity to give it a try.