You are restricted to the original resolution that was acquired when you took the picture. You can't make it a higher resolution than what was initially taken.
It depends on the brand of monitor and it's capabilities also what you have your monitor set to display in the screen resolution setting in your control panel.
"Typical circa- 2000 cathode ray tube...
If you mean "What does pixels per inch mean?" then I can help. This refers to the density of pixels within a given inch squared of an image. Basically its an easy way to determine the quality of an...