Public IP vs private IP vs gateway IP
Your public IP is the globally routable address your ISP assigns to your broadband line or phone; that is what this page shows. Private IPs (192.168.x.x, 10.x.x.x) only exist inside your LAN and are handed out by your router; the internet never sees them. The gateway IP is usually the router's own LAN address (e.g. 192.168.1.1), your first hop to the internet.
Every device in the same home or office shares one public IP through NAT, so the address you see here matches what another device on the same Wi-Fi would see.