Bluetooth Mesh and Zigbee are both wireless mesh networking technologies for smart lighting. Bluetooth Mesh operates on the 2.4GHz band using Bluetooth Low Energy (BLE), with each device relaying messages. It doesn't require a dedicated hub for basic operation (a smartphone can control directly), supports up to 32,000 nodes, and is backed by the Bluetooth SIG. Zigbee also uses 2.4GHz, requires a coordinator/hub, supports up to 65,000 devices, and has a longer track record in commercial installations. Bluetooth Mesh advantages: no hub needed for basic use, easy setup via phone app, growing ecosystem (Signify/Philips Hue, IKEA). Zigbee advantages: more mature commercial tools, better interoperability certification, proven scalability for large sites. For consumer/small commercial, Bluetooth Mesh is increasingly popular. For large enterprise projects, Zigbee or wired DALI remains more common. Both can coexist in hybrid systems.