Megapixels refer to the resolution of a digital image, indicating the number of pixels it contains. One megapixel equals one million pixels. Higher megapixel counts generally allow for more detailed images, making them suitable for larger prints or cropping without losing quality. In cameras, such as those found in smartphones or DSLRs, megapixels are often highlighted as a key feature. However, while more megapixels can enhance image quality, other factors like lens quality and sensor size also play crucial roles in overall photography performance.