I suspect that you really want to know if you extend the range of a wireless router by using a repeater or bridge. Repeaters do extend range by relaying traffic from one set of stations to an upstream (root) access point. The problem is that the repeater does double-duty, participating simultaneously in two WLANs (as a station in the root WLAN and as an AP in the repeated WLAN). The repeater must also be positioned with significant overlapping coverage so that it gets good signal from the upstream AP.
Wireless bridges do something else entirely. They link separate wired networks (ethernet LANs) together using wireless as the backbone link between them. This does not affect range, with one caveat: point-to-point connections between bridges may actually reach farther by using antennas that focus signal more narrowly in one direction.
This was first published in July 2003