Projector Resolution

A projector's resolution (or more precisely, its "native resolution") is simply the number of pixels that it has available to create an image. The higher the resolution of a projector, the more pixels it has.
Projector resolution is designated with either one or two numbers. A typical two-number resolution might be listed as "1280x720." The first number indicates how many pixels there are in each horizontal row, and the second number is how many pixels make up each vertical column. If you were to multiply the two numbers, you would end up with the total number of pixels on the display device. Often, a projector's resolution will be referred to by one number, such as "720p" or "1080p." This designation refers to the vertical resolution, or the second number in the two-number designator, while the "p" refers to progressive-scan, which simply indicates that the entire picture is displayed at the same time.
The advantages of higher resolutions are that (a) they can display more detail in the picture (assuming the video signal has the detail in it), and (b) they reduce or eliminate the visibility of the pixel structure.

Common Resolutions:
Projectors come in a variety of different resolutions, including the following:
1280x720: For a long time, this was the most popular home theater projector resolution on the market. Most 1280x720 projectors offer very good to excellent DVD video quality. They also do a beautiful job of displaying 1080-line video, such as the 1080p found on Blu-Ray discs or the 1080i of broadcast HDTV.

1280x768: This is a hybrid resolution that combines the ability to display 16:9 video in 1280x720, as well as standard computer resolutions XGA(1024x768) and WXGA (1280x768), in native form without scaling. If your viewing material includes both video and computer data or Internet surfing, this format will allow you to see the computer data signals in their clearest, unscaled form. Note that this is a 15:9 aspect ratio rather than 16:9 as are the others in this list. So when you are viewing 16:9 video material, there will be small black bars at the top and bottom of the projected image. That is the penalty you pay for having those extra 48 lines available to accommodate XGA computer signals. A variant of this format, 1280x800, can display 1024x768, 1280x720, 1280x768, and 1280x800 signals natively.

1920x1080: The ultimate high definition format; it will display HDTV 1080i signals, as well as 1080i and 1080p signals from Blu-ray disc players, all in native format without any scaling. This gives you the sharpest and most detailed images available today. Due to the pixel density, visible pixel structure is virtually non-existent.