Parcel includes a development server out of the box supporting hot reloading, HTTPS, an API proxy, and more.| parceljs.org
webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset.| webpack
The WebSocket object provides the API for creating and managing a WebSocket connection to a server, as well as for sending and receiving data on the connection.| MDN Web Docs