Direct view tube tv's use scanning lines instead of pixels. This inherent analog technology allows multiple resolutions. A hi def tube tv can be made to display 480i, 480p, 720p, and 1080i along with several others such as 540p. However, to keep price points low, the consumer models do not display all the resolutions. They would display 1080i and not 720p, so there is conversion on the vertical resolution. Also, they do not display the full horizontal resolution such as 1920 in a 1920x1080i program. However, tube tv's have outstanding picture and are much more affordable. Hope this helps