Settings help you to customise your software. They are very powerful, and each user should take the time to look through them and set them up. These particular Settings let you set AVA's monitor resolution to that of the monitor you are using.  The default is 72 dpi. 

When displaying an object at actual size (100% scale) on a 114 dpi monitor, if you left this setting at 72dpi, your design would appear smaller on the screen than it is in reality, and this would become immediately obvious when you print your file.

To set the correct monitor resolution for AVA, simply click Set. The resolution of the main monitor will then be displayed in the Monitor Settings Window.