A dual WAN router is one that that has multiple WAN (incoming) ports available for multiple Internet Access accounts (Broadband, ADSL, Cellular, etc). Essential to this function is a software capability that will let the router automatically switch accounts (depending on the limits set by the technician). This function has two distinct benefits. First, it saves money by keeping the main broadband account under the data limit set by the provider (usually 250gb, before overage charges begin). Second, it allows a smaller sub-network setup for the public WIFI system, thereby limiting customers use to email, text messaging, etc.