In the latest routers, where switching function is integrated into the box will have few LAN ports (say usually, 4 or 8) and 1 WAN port.
Usual configuration would be to connect computers or printers onto the LAN port and WAN port onto the modem to connect to the internet.
So is it like the LAN ports are nothing but the ports of the integrated switch? And WAN port is used to connect to a separate subnet, say to an another switch or to an another router? (Internally, it would be like integrated switch is connected to an another hidden WAN port*)