xbee Coordinator - is this Tx or Rx

I am trying out the examples that came with xbee.h library. I configured my two xbees, one as coordinator and one as the end device. There is a sample Tx and sample Rx sketch (I'm using Series 1). Should I load the Tx sketch onto the Arduino with the coordinator xbee?

I figured it out, the Coordinator is the xbee receiver.

I just did some more testing and realized it doesn't matter, either XBee and transmit and receive.