connect-livereload is a middleware for Connect-compatible web servers that injects the livereload script into HTML pages. This enables automatic browser refreshing when you make changes to your files during development. By inserting the script, it provides a seamless workflow for front-end developers, updating the browser with the latest changes in real-time. It simplifies the development experience by eliminating the need for manual refreshes and integrates with other build tools to monitor file system changes.