Key Difference: Pixels are a basic measuring unit in computer imagery. They collectively create images that one can see on a digital screen display. Resolution is the term that is used to describe the crispness and detail of an image. In optics, it is most commonly described as the ability of an imaging system to resolve detail in the object that is being imaged.

Pixel and resolution are two important concepts that are used together in photography. Both are usually used when referring to camera and printer settings. Though these terms are used simultaneously and one concept plays a greater part in the other; they differ from each other in various ways.

Pixel is basically a mixture of ‘Picture' and 'Element’. Pixels collectively create images that one can see on a digital screen display. Generally, the higher the pixel counts within a digital image, the sharper the image. A digital camera usually produces better images because they produce a higher pixel count. It makes the image more suitable for enlargements and allows more possibility for image cropping. Pixels are a basic measuring unit in computer imagery. It is used in cameras, screens, TVs, etc., anywhere an image is displayed. It is also considered as a physical point in a raster image or the smallest element that is displayed in an image. An image is often made up of small pixels that come together to form a bigger picture. Pixels can also be used as color dots to create a whole image, where pixels represent colors in the image.

Notice when an image is magnified to its full extent, it shows tiny squares that make up the picture. These are pixels; these pixels together make up the image that is being displayed. Screens and TVs that are available these days come with a fixed pixel amount, which is given under resolutions. This determines the quality of the image that would be available on the screen. The higher the resolution, the higher the pixel count, which results in a better image.

Dictionary.com defines ‘Resolution’ as:

• The process or capability of making distinguishable the individual parts of an object, closely adjacent optical images, or sources of light
• A measure of the sharpness of an image or of the fineness with which a device (as a video display, printer, or scanner) can produce or record such an image usually expressed as the total number or density of pixels in the image <a resolution of 1200 dots per inch>
• In Physics & Chemistry: The act or process of separating or reducing something into its constituent parts: the prismatic resolution of sunlight into its spectral colors.
• The fineness of detail that can be distinguished in an image, as on a video display terminal.

The amount of detail that the camera can capture is called resolution. It is determined by the dimension of the unit of information representing an image. In optics, resolution is the ability to distinguish two separate objects. The resolution of a system is based on the minimum distance at which the two objects can be separated and distinguished as individuals. The resolution depends on the aperture of the instrument and the wavelength of the observed light. The resolution of digital images can be described in many ways including pixel resolution, spatial resolution, spectral resolution, temporal resolution and radiometric resolution.

Resolution can be measured in 3 ways:

• Sample per inch (spi, scanners)
• Pixel per inch (ppi, monitors)
• Dots per inch (dpi, printers)

Comparison between Pixel and Resolution:

Image Courtesy: sammobile.com, upload.wikimedia.org