Marcus Battle's tutorial offers a comprehensive guide on creating a WebSocket server in PHP using the Ratchet library to facilitate real-time bi-directional communication between clients and a server. Despite PHP's lack of native support for WebSockets, Ratchet emerges as a powerful tool for real-time development, enabling low-latency connections that allow both clients and servers to send and receive messages simultaneously. The guide walks through setting up a basic WebSocket server using PHP 7+, Composer, and ngrok, illustrating the process with a simple chat application that displays messages in real-time across multiple browsers. Key components include creating a WebSocket class with essential methods like onOpen, onMessage, onClose, and onError, and setting up an HTTP server to listen on port 8080. The tutorial concludes with instructions on testing the server and highlights the necessity of running the server as a background service to maintain persistent connections.