Are you talking about "4th Gen" "3rd Gen" etc? It just means the change in body style. For instance, they made "1st Generation" 4Runners from 84-89 If you look at them, they all look pretty much the same. In 90, Toyota introduced the 2nd Gen, which was a total redesign. Then the 3rd Gen in 96 (95.5, actually), then the 4th in 03, which is the current design.
