1080i

1080i refers to the ATSC high-definition interlaced format used to show images on high-definition (HD) video displays. This means the display can paint 1080 lines of information per frame. A frame is made up of two fields. The first field displays the odd numbered lines, then the second field displays the even numbered lines.

16:9 (16x9, 16-by-9)

This is a widescreen aspect ratio (width by height) used for video display. The displayed image is 16 units wide by 9 units tall, similar to the screen at a movie theater.

The 16:9 aspect ratio is the one of the new standards for digital television broadcasts.

4:3 (4x3, 4-by-3)

This is the traditional, nearly square aspect ratio (width by height) used for most current analog television screens. The displayed image is 4 units wide by 3 units tall. Most current TV programming is in 4:3 format.

480i

480i refers to the interlaced format used to show images on video displays. This means the display can paint 480 lines of information per frame. A frame is made up of two fields. The first field displays the odd numbered lines, then the second field displays the even numbered lines.

480p

480p refers to the non-interlaced (progressive) format used to show images on video displays. This means the display sequentially paints 480 lines of information per frame. In an interlaced format, a frame is made up of two fields. The first field displays the odd numbered lines, and then the second field displays the even numbered lines.

5.1

“Five point one” is a term used to describe a digital surround sound audio format. The “5” stands for five discrete channels of sound information: left front, front center, right front, right rear or surround, left rear or surround. The “.1” is a sixth channel designated for a subwoofer. A full 5.1 digital audio system can provide stunningly realistic sound.

720p

720p refers to the ATSC non-interlaced (progressive) digital format used to show high-resolution images on HDTV video displays. This means the display sequentially paints 720 lines of information per frame.

In an interlaced format, a frame is made up of two fields. The first field displays the odd numbered lines, and then the second field displays the even numbered lines.

When progressive scan is used, the image quality is less distorted and overall image quality is better. In order to take advantage of HD progressive scan, you need a high-definition video display.