Scan Lines: A TV picture is a lot like a Monet painting, up close it looks like a confusing mess of crap, but back up a few feet and you'll be viewing a masterpiece. If you've ever taken a really close look at the screen of your TV, you can actually see that the picture is made up of individual lines running in a horizontal direction across the screen. These are called Scan Lines. The number of scan lines contained in a normal TV broadcast is 525, but only 480 are used to make up the actual picture that you see. Generally speaking, the greater the number of lines, the more detail the picture will have. This is where HDTV gains its huge advantage over SD (Standard Definition). A High-Definition (HD) signal is comprised of 720 or 1080 lines of resolution as compared to just 480 lines for Standard Definition (SD). But as you'll soon see, lines are not the only factor in determining a picture's clarity, the way the lines are drawn on the screen is equally important.

Interlaced vs. Progressive Scan: The lines can be drawn across the screen using two methods, Interlaced or Progressive. Interlacing (i) requires two separate passes across the screen to display the picture. The picture's lines are broken up into 240 odd and 240 even rows, and each row is drawn on the screen in a separate pass. In essence you are only seeing half the picture at a time, but the TV draws the lines so quickly that your eye perceives the image as complete. The second method, known as progressive scan (p), draws the entire picture in one pass. The computer monitor you are reading this page on is progressive scan. Progressive scan is superior to Interlacing, as it produces a smoother, flicker free image. A HIGH-DEF image can be either Interlaced at 1080i (1080 lines) or Progressively scanned at 720p (720 lines).

Since you'll be relying on an external Satellite Receiver to supply the HD signal to your TV, the way in which that signal is delivered can be one of the most vital areas of concern when purchasing HD equipment. You must always keep in mind that HD pushes video to the max, and therefore the quality of the signal delivered to your TV will have a much greater affect on the image than with SDTV. Cables and connection methods are often overlooked by most consumers since their differences are usually detected only by those with highly trained eyes.. This is not so with HDTV.

Know Your Display Type: First things first.. You must know what type of display you'll be using before you can decide on connection methods. Plasma's, LCD's, and DLP's, are all Digital displays, while CRT's are Analog. Keeping the digital HD signal in its native digital format (no digital to analog conversion) will almost always result in a better picture. Therefore the type of connection you choose should limit this conversion process as much as possible.

VIDEO Connectors: (Analog vs. Digital) Up until now the most common connection method has been "Component Video". This type of connection is analog, which means that the signal needs to be converted from digital to analog for transmission. It uses 3 separate cables to send the video signal to your TV. Component connections are acceptable for HD, but the conversion will ultimately result in slight signal degradation. However, if you have a CRT Display, using component will prevent having to convert the signal back to digital once it reaches your TV. The second method is DVI (Digital Visual Interface). You may be familiar with this type of connection because it is often found on many higher-end computer monitors and video cards. This is the preferred method by which to connect your digital HD components to your digital display, since it has extremely high bandwidth, and will also keep the signal in its native digital format. There is a noticeable increase in picture quality when viewing HD material via a DVI Connection.

AUDIO Connectors: (Optical vs. Coax) The Dolby Digital audio that accompanies an HDTV signal can be carried by either an Optical or Digital Coax cable. Optical cables have an advantage because they are not affected by electromagnetic interference, and are capable of running over longer distances without degrading.

VIDEO/AUDIO Connectors: You may have begun to hear a lot about HDMI (High-Definition Multi-Media Interface). HDMI is a connection method similar to DVI, but goes one step further by carrying both HD Video and Audio over a single cable. This will prove to be very popular as it greatly reduces the cost and complexity of connecting HD components together. HDMI is supported by many new products, and is currently available on HD Satellite Receivers from DirecTV and DISH Network.