We typically use that term in referring to a load balancer which balances workload of a set of servers using some sort of Virtual IP or VIP. Products like a Citrix Netscaler or F5 Local Traffic Manager (LTM).
In the context of a router you can balance outbound links using a dynamic routing protocol like BGP but it depends on your service provisioned at the site. You can balance inbound traffic using a first hop redundancy protocol like HSRP. All Cisco routers do that to some level but which one to choose depends on throughput and speed requirements.
I know the basics for Cisco routers and switches but what I want to know is, if I set up VTP on a switch, is there a way to send it through routers to other switches? This will probably end up more hassle than gain, but it's interesting and cool to p...