Difference between Client Bridge and Repeater Bridge
A standard wireless bridge (Client Bridge) connects wired clients to a secondary router as if they were connected to your main router with a cable. Secondary clients share the bandwidth of a wireless connection back to your main router. Of course, you can still connect clients to your main router using either a cable connection or a wireless connection.
The limitation with standard bridging is that it only allows wired clients to connect to your secondary router. Wireless clients cannot connect to your secondary router configured as a standard bridge. Repeater Bridge allows wireless AND wired clients to connect to a the Repeater Bridge router, and through that device wirelessly to a primary router. You can still use this mode if you only need to bridge wired clients; the extra wireless repeater capability comes along for free; however, you are not required to use it.