What is the maximum resolution of a plasma TV?

For broadcast signals there are two formats. 1920 x 1080 is one and 1280 x 720 is the other. Although the 1080 line image has more pixels, the 720 line signal updates the image at twice the rate of the 1080 image so the amount of data used for each is the same. They formats are commonly referred to as 1080i and 720p.

The i stands for interlaced meaning that the image is updated in two passes of the screen, odd number lines first and then the even numbered lines on the next pass. The p stands for progressive meaning that the image is updated fully in a single pass, hence 720p is updated at twice the rate of 1080i

Local sources such as Bluray and games consoles can output 1080p as well as other HD formats. The image is refreshed twice as fast as 1080i but the resolution of the image is identical.