The Nodemon Webpack Plugin is a development tool that combines webpack's build process with Nodemon's file-watching and server-restarting capabilities, allowing developers to automatically restart their server whenever source files change during development. It's designed for Node.js developers using webpack who want to streamline their development workflow by eliminating the need to run webpack and nodemon as separate processes. The plugin is particularly useful for backend development where you need to see changes reflected immediately without manually restarting your server.