what is the difference between a vga and megapixel camera?

A megapixel camera has more pixels than a VGA camera, so typically the images taken will be clearer because more pixels means more colors and details.  VGA camera is the most basic camera included on cell phones, followed by 1.3MP, 2MP and higher megapixels for greater image clarity. Typically, you pay more in a phone for more megapixels.