Megapixel
A megapixel is one million individual pixels. A camera's total resolution, computed as image width in pixels times height in pixels, is usually stated in megapixels — a 24-megapixel camera on a standard 3:2 sensor produces roughly 6,000 by 4,000 pixels.
Megapixel count directly determines two things with real practical consequence: maximum comfortable print size at a given viewing distance, and how much an image can be cropped before quality visibly degrades. It does not determine dynamic range, color accuracy, autofocus quality or overall image sharpness in any holistic sense — those depend on sensor technology, lens quality and processing, largely independent of raw pixel count.
Frequently Asked Questions
Does more megapixels always mean a better camera?
No — past a fairly modest threshold for most practical print and screen use, additional megapixels mainly buy extra cropping headroom and larger print capability, while overall image quality depends far more on sensor technology, lens quality and processing than on resolution alone.
How many megapixels do I actually need?
It depends entirely on your largest realistic print size and how aggressively you regularly crop — for most photographers, 24 megapixels already comfortably covers typical print and screen needs with real room to spare left over.