Free-to-air Adapters (FTA) - Free-to-air Adapters are a type of device that can be used to receive and interact with Free-to-air Services. These services are easier to receive as these tend to not be encrypted.

Free-to-view (FTV) - These services are often digitally encrypted and may be restricted geographically. FTA services
generally are available without a subscription.

See the Interactive Television Institute.