The highest video resolution supported by the PowerShot D20 is 1920 x 1080 pixels. That's over two times the video resolution of a 1280 x 720 pixels camera, which is the most common video resolution supported by cameras of this age and spec. 1280 x 720 pixels is also supported by this Canon camera. This camera also support a video resolutions of 320 x 240 pixels and 640 x 480 pixels. A video resolution of 1920 x 1080 pixels is equivalent to Full HD video. You will require a Full HD TV or better to appreciate this level of detail.
This camera's video resolution (1920 x 1080 pixels) is actually the best supported video resolution across all digital cameras that have been around for around the same time as this camera.
A 320 x 240 pixels video resolutions is the worst supported video resolution amongst comparable types of camera.
What does "video resolutions" mean?