Difference Between 1080i and 1080p HDTV

High definition TVs (or HDTVs) use numbers to define their screen resolution. 1080 is the highest possible resolution as of this writing, but there is a subtle distinction between 1080p and 1080i. Those letters have a bearing on the screen's overall clarity, so it pays to know exactly what they mean before making a purchase.

The Number

The number refers to the horizontal pixels which make up the screen. An HDTV with 1080 resolution thus has 1080 horizontal pixel lines on its screen.

The "I"

The "i" after the number stands for "interlaced." That means the screen flashes back and forth between one half of the pixels and the other half: it looks like a single image to the naked eye, but is responsible for the flickering effect of many TVs.

The "P"

The "p" stands for "progressive." That means every horizontal line on the screen broadcasts at the same time for a fully integrated picture.

HDTV

Screen resolution comes into play with HDTV in particular, since shows broadcast in high definition are very sharp and clear. How sharp depends on the clarity of your TV set.

The Difference

The difference between 1080p and 1080i is small but noticeable. 1080p provides a slightly clearer image--the best on the market right now--though 1080i is usually slightly cheaper.