A high speed USB host controller is refers to the speed at which the USB port is able to handle information. The first USB controllers offered approximated 12mbps (megabytes per second), although this seems pretty fast, at least it was in the old days. You know technology changes at the drop of a hat, and so the speed increased over time to a 480mbps. Keep in mind, if you have a slower host controller, you can still use the faster devices but it will only run at the slower speed. Just between you and me, it is really not a noticeable difference.
