What's the difference between WAN and LAN?

WAN ports connect a router to the ISP’s network and receive the public IP address, while LAN ports link local devices and assign them private IPs for intra-network communication. Wi-Fi serves as a wireless LAN, allowing devices to access the local network and, via the WAN port, the internet; guest Wi-Fi creates an isolated LAN that can reach the internet but not other local devices.