Understanding Resolution

A resolution of 800 x 600 means that the entire monitor shows a grid that’s 800 pixels wide and 600 pixels high. A pixel is the smallest unit of measurement on a computer monitor, and is otherwise known as "dot". A resolution of 800×600 gives 480,000 pixels. Whil 640 x 480 resolution gives 307,200.

A screen resolution isn’t tied to the size of monitor. A 17" monitor can have a higher resolution than a 19" monitor. However it makes sense for a larger monitors to use higher resolutions. That’s because on a small monitor, high resolution looks cramped. Monitors support awide range of resolutions, and you can choose the best compromise between showing lots of content (a higher resolution) and making sure that content isn’t too small (a lower resolution).