Question : Problem: I need a wireless network bridge for my old iMac.

I have an old imac that does not have an airport card slot but it does have a network port.  I need a wireless network bridge like the D-Link 810+.  I was thinking of getting an external AirPort Access Point, but I don't need an Access Point, I need a bridge, my question is can I use the AirPort Access Point as a bridge or is it only supposed to connect to the WAN (cable modem) and what is the difference between the AirPort Access Point and an AirPort Base Station?  My wireless router is a D-Link so I will probably end up getting the 810+ and try to connect it to the iMac, unless they make an AirPort Bridge, but I haven't seen one.

Answer : Problem: I need a wireless network bridge for my old iMac.

Yes but obviously some will run it better than others. Any current iMac will and for older ones I'd only recommend it for iMacs of 400mhz or better with more than 256 mb ram.