Dumb wireless networking question

I have a little bit of a stupid wireless question. I have two wireless routers, one is my main wireless router. The other I would like to setup wirelessly, as an access point. In other words I would like to pretty much like to be able to "repeat" the signal and be able to utilize the LAN ports on the secondary router. My question is, is this a bridge, a WAP, or is it something else? I am not sure how to configure it, and have instructions for each. Please let me know, any and all help is much appreciated.