A television's resolution is measured in two ways:
- How many pixels it can display vertically on the screen. As mentioned, an HDTV can display at least 720 vertical pixels. A lower resolution DTV may only display 480 pixels or fewer. Again, the more pixels, the better the picture.
- How the picture is drawn (scanned) on the screen. This can be either all at once ("progressive scan") or in two passes ("interlaced scan") – abbreviated "p" and "i," respectively. Progressive scan provides a smoother, flicker-free picture.
High Definition sets can offer resolutions of 720p, 1080i, and 1080p. 1080p is a great match for many HD video games and required for anyone who wants the full Blu-ray experience, as Blu-ray is 1080p "native" (i.e., not upscaled) resolution.
For watching standard HD programming, your customer needs a set that can display 720p or greater.