A megapixel is a unit used to measure the resolution or number of pixels in an image. In the context of photography, a megapixel camera refers to a digital camera that captures images at a high resolution, typically measured in millions of pixels (2-3 million pixels). This means that the resulting photos taken by such a camera will have more detail and clarity compared to lower resolution cameras. The higher the number of megapixels, the greater the potential image quality.