OTA = Over The Air, it is an antenna to pick up local digital broadcast channels. The 722 has one tuner built into the receiver so you can incorporate the channels into your guide adding one of the available channel to view or record. The 722k does not have any tuner built in, but you can buy the OTA module for it at several places including Dish, and this one will add two local digital broadcast channels to view or record. As far the antenna type you need or more info, you can checkout antennaweb.org or tvfool.com.