What is the difference between a high pixel camera and a low pixel camera?

Higher mega pixel cameras offer the ability to print larger images. For example a 6mp camera offers a resolution of 3000 x 2000 pixels. If you allow 300dpi (dots per inch) for print quality, this would give you a print of approx 10 in x 7 in. 3000 divided by 300 = 10, 2000 divided by 300 = approx 7 A 3.1mp camera offers a resolution of 2048 x 1536 pixels which gives a print size of 7in x 5in You can make bigger images, but you would need to accept that you would lower the quality of the image.