Your traditional television is known as an analog (analogue) television. It works by encoding the picture and sound information as an analog signal. The picture on an analog television is drawn on the screen one entire frame at a time. The analog signals are transmitted continuously even if there is no new information to send.

A digital television receives information as a digital signal. This is an entirely new technology and will eventually replace the analog television system.

The digital signals are transmitted using computer code, which consist entirely of ones and zeroes. This is a difficult concept to perceive but it works.

Another significant feature of digital television is that is uses a significantly smaller channel bandwidth. This means there is more 'space' for other digital channels which will allow other non-television services such as pay-multimedia services, multi-casting (more than one program on the same channel), electronic program guides and interactivity to be used at the same time.
Whilst digital television often has superior audio quality, image, and reception than analog, it is still in the early stages of development and there are still many advances needed.

As with most things in today's modern society Digital Television comes in a couple of quality levels:-

Standard Definition TV (SDTV) - This is the basic level of digital television transmission. It has a quality similar to today's analog TV;

Enhanced Definition TV (EDTV) - This gives a better level of quality and includes Dolby digital surround sound;

High Definition TV (HDTV) - This as the name suggests gives the best quality digital picture and Dolby digital surround sound.

Currently, most TV stations in America are broadcasting digital and analog. This means that you can view your favorite TV shows no matter what type of TV you have. However, after the 17th February 2009 the full-power TV stations will no longer be able to broadcast in analog.

And if you have an analog TV you will not be able to view the shows unless you obtain a separate digital-to-analog converter box or a new digital TV.

Bear in mind though, that an analog TV connected to a digital converter box will display the digital broadcasts but not in full digital quality. However, if you are currently plagued with interference such as electrical static, of if you have ghost or snowy pictures then your current TV will look like a high definition upgrade because digital eliminates all of that.

Digital TV is already available over the air using a standard antenna or via digital cable or satellite. No matter how you receive your TV signal (satellite, cable or over-the-air), you will need the digital converter or digital TV to watch the programming.