A large chunk of bandwidth available without interference at 2.4 GHz allows companies to design radios that move data fast. Sensitive receivers for these high-band systems are, however, difficult to design, and the shorter radio waves bump into snowflakes and water droplets, so the reliable ranges are limited. All of these products continuously pass along all packets if needed. But some of them have other tricks. When WAN links are slower than the LAN cable, smart bridges can keep unnecessary traffic off the slower WAN links.
Bridges can also serve as internal security devices.
You can set up a bridge to reject all traffic except that from specific legitimate nodes. Since the bridge reads addresses encoded into LAN adapters, successful spoofing is highly unlikely. Network planners should note that each radio link is its own collision domain and retimes Ethernet packets. So you have to add the radio link into your hop count. Clarion's MerLAN M10 wireless transceiver is a breakthrough product.