Terrestrial TV (Transmission) - (Maybe known as, or associated with Free-to-air-TV, Free-to-air Digital Television, Digital Terrestrial Television, Commercial Terrestrial Broadcaster, Broadcast Over the Air, Over-the-air, or OTA, Terrestrial DBS,  Terrestrial Communications, Wireless Cable, Wireless Cable TV, Multichannel Video Distribution System, MVDS, Microwave TV.) – Terrestrial TV is television transmission using one or more transmitters that located on the ground. Alternatives include Cable, Telco and Satellite TV transmission. Analog television was initially transmitted via terrestrial transmission. Terrestrial TV is more common in Europe than the States.

Digital Terrestrial Television (DTT) - The delivery of television into the home/business through an ordinary TV aerial. ITV Digital in the UK (formerly "ONdigital") was the first company in the world to offer this. Interactive television is possible if a return path is provided.

Digital Terrestrial Broadcasting – (DTB) - DTB can be received anywhere and at anytime with a small reception antenna. Via DTB, end-users (customers) can watch programming and receive other data that has been transmitted to compatible wireless devices. See DTT.

Interactive Digital Terrestrial TV
– (IDTTV, Interactive Digital Terrestrial TV Network) – Digital terrestrial television systems that offer the user multiple functionality including interactive television. These have one or more return path(s) from the end-user (viewer) to the network operator.

Terrestrial-based Internet-over-TV – Internet services often viewed via TV which are sent to the end-user via Terrestrial Transmission.

Terrestrial DBS – A digital broadcast system that instead of using satellites to send all their signals, uses wireless transmitters that are located on the ground. See Terrestrial TV and MMDS. It's used more in Europe than the States.

Terrestrial Communications (Systems) - It may utilize UHF as a frequency and COFDM for modulation. End-users can use their old antenna or upgrade.  They'll need a set-top box or equivalent device to decode the digital signal.  It was first commercially sold in England in November of 1998. See Terrestrial TV.