Here's a little on digital image resolution
First, some terminology:
Digital photography is a form of photography that utilizes digital technology to make digital images of subjects. Until the advent of digital technology, photography used photographic film to create images which could be made visible by photographic processing. Digital images can be displayed, printed, stored, manipulated, transmitted, and archived using digital and computer techniques, without chemical processing.

Image resolution describes the detail an image (see definition below) holds. The term applies equally to digital images (a representation of a two-dimensional image as a finite set of digital values, called picture elements or pixels. The digital image contains a fixed number of rows and columns of pixels. Pixels are the smallest individual element in an image, holding quantized values that represent the brightness of a given color at any specific point.), film images, and other types of images. Higher resolution means more image detail.
Pixel resolution The term resolution is often used as a pixel (see also below) count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field. An image of N pixels high by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as resolution, the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 640 by 480. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions, but they are widely referred to as such; they serve as upper bounds on image resolution.
The links below present the same image displayed in each of the resolutions that the cameras
I have owned supported.  Each image links to the next higher resolution image.  The images  were
cropped (but NOT enlarged) to show the full-resolution detail as it would appear in the full sized version.  
I opted not to put the full-size images here since, for instance,  a 10.2 Megapixel image can be nearly
5 MB in size and would be REALLY slow to download.  Click on one of the cameras to start:
QV-11 DC260 CoolPix D70s D80

IMAGE: In common usage, an image (from Latin imago) or picture is an artifact, usually two-dimensional, that has a similar appearance to some subject—usually a physical object or a person.  Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue. They may be captured by optical devices—such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces. PIXEL: A pixel (short for picture element, using the common abbreviation "pix" for "pictures") is a single point in a graphic image. Each such information element is not really a dot, nor a square, but an abstract. With care, pixels in an image can be reproduced at any size without the appearance of visible dots or squares; but in many contexts, they are reproduced as dots or squares and can be visibly distinct when not fine enough. The intensity of each pixel is variable; in color systems, each pixel has typically three or four dimensions of variability such as red, green, and blue, or cyan, magenta, yellow, and black.

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