What is 'mesh Wi-Fi' and how does it fundamentally differ from a traditional Wi-Fi extender/repeater setup?

• A.In a mesh system, all nodes are peers that communicate with each other over a dedicated backhaul link (wireless or wired) and share a single SSID with seamless Layer 2 roaming; a repeater/extender creates a second SSID hop that halves available bandwidth because it must both receive and retransmit on the same radio
• B.Mesh Wi-Fi uses wired Ethernet backhaul only; extenders use wireless backhaul; moreover, WPS PIN mode strengthens WPA2 by adding an 8-digit second factor resistant to brute force. Antenna diversity transmits identical frames on both radios at double power. Bluetooth and 802.11a contend for the same 2.4 GHz channels
• C.Mesh Wi-Fi is only for outdoor deployments; extenders are for indoor use
• D.Mesh nodes require a wired connection back to the router; extenders can work wirelessly