A hub or gateway is a single centralized hardware device that connects to a home wireless network. It acts a bridge to your home router to help control multiple smart devices such as a smart light bulb or a smart socket. A hub is useful when you have products that uses wireless protocol such as Z-Wave, Zigbee. With STITCH products, the bridge is already built-in to the products to help easily connect directly with your home wireless network, so save your money, there’s no need to purchase a separate hub.