Definition - What does Megapixel (MP) mean?
Techopedia explains Megapixel (MP)
The megapixel count determines how large the image can be printed without a loss of quality. For example, a 1.3 megapixel cell phone camera can take images that are good for printing of up to 4x3 inches. If the image is blown up beyond that size, image quality degrades dramatically.