Tri-bands & smart switching
A tri-band router has a 2.4GHz network and two separate 5GHz networks, whereas a dual-band router only has a 2.4GHz and a 5GHz network. Having two 5GHz networks can potentially double the speed of data being transferred over the 5GHz network.
Smart switching lets a router with two 5GHz networks distribute the workload over both networks simultaneously. This means if one 5GHz network is too busy or overloaded, then the router will use the other 5GHz network to pick up the slack.