Can you define HDTV terms that I might need to understand?

HDTV stands for high-definition television. HDTV can have a resolution of more than 1,000 horizontal lines of colored dots, which means that an HDTV signal displays roughly four to six times the detail of an older analog television.

Here are some other terms that you should learn the meanings of:

480i, 720p , 1080i and more are possible resolutions of an HDTV.  The numbers represent horizontal lines of colored dots on the screen. The letters indicate the type of scanning used, either "interlaced" or "progressive".

The higher the number, the sharper the picture.  However, getting the most out of HDTV is not always that simple. Sporting events, for example, are best displayed at 720p because the screen refreshes faster, thus showing action better.

All of our Set-Top Boxes are capable of displaying any of these HD resolutions.  

Aspect ratio is the width of a picture relative to its height. For example, 4:3 and 16:9 are common aspect ratios. Virtually all HDTV transmissions are in 16:9 aspect ratio. Some HD TVs are 4:3 but display 16:9 programming in letterbox format (black borders on the top and bottom of screen).

Use the steps below to adjust the aspect ratio on most of our Set-Top Boxes:

  1. Press SETTINGS.
  2. Use the left/right arrows to navigate to HIGH DEFINITION.
  3. Use the up/down arrows to navigate to Aspect Ratio.
  4. Select a setting from the options displayed.

If these instructions don't work for your Set-Top Box, go to our Customer Support page, select TV and then Cable Boxes from the menu and refer to the equipment manual for your model.


Digital Visual Interface (DVI) is an all-digital link between a video/audio source such as an HDTV Set-Top Box and a display device such as an HDTV. DVI connectors transfer video signals in pure digital form, which is especially beneficial if you're using a plasma, LCD or DLP TV. The DVI link does not contain audio, so audio is still needed to be connected from the Set-Top Box to the HDTV or home theatre system. One advantage of DVI is that the link allows graphics to be sent along the link as well. This allows the user interface from the Set-Top Box to be displayed on the HDTV. There are two types of DVI connectors: DVI-D carries digital-only signals and DVI-I passes both digital and analog video signals. Some TVs feature DVI-I inputs for greater hookup flexibility.


Digital Television (DTV) is a type of television signal. DTV can be watched on any standard television if you have a digital Set-Top Boxes. DTV can also be watched in high-definition if you have an HDTV television and an HD Set-Top Box.

High-Bandwidth Digital Content Protection (HDCP) is the copy protection standard that is tied to DVI.

High-Definition Multimedia Interface (HDMI) is the next generation of DVI. The main difference between HDMI and DVI 1.0 is that HDMI adds audio to the DVI link and is a smaller connector. The HDMI interface will be backwards compatible to the DVI 1.0 interface, meaning that you can connect up a Set-Top Box to an HDTV, where one has DVI 1.0 and the other has HDMI. Most new HDTVs have HDMI. Those that don't most likely are equipped with DVI, which is backwards compatible.

YPbPr is the component video format in which the luminance (Y) is represented separately from the color components (Pb and Pr). The majority of HDTVs today support this format. These HDTVs accept the YPbPr formatted video per EIA specification 770.3. The Y output on HDTVs and HDTV receivers is provided as a green jack, the Pb is provided as a blue jack, and the Pr is provided as a red jack. The colors themselves are not to be confused as an RGB output. The Explorer 3100HD has a YPbPr output only.