The smaller the size of a pixel and larger the number of pixels the higher the resolution and therefore the picture clarity. The pixel can be defined as the smallest of the homogeneous units in color that make up a digital type image. Enlarging one of these images through a zoom it is possible to observe the pixels that allow the creation of the image. In front of the eyes, they appear as small squares or rectangles in white, black or shades of gray.
The larger the pixel size, the greater the amount of light captured from photosensitive components, this results in a higher sensitivity without noise or less quality in the image. Also, the size of the pixel influences how to represent high contrast situations. The smaller the size, the better resolution, but lower sensitivity. The larger the size, the better sensitivity but lower resolution.
In color monitors, the number of bits used to represent each pixel determines how many colors or shades of gray they can represent. Each pixel is composed of three cells, one red, one blue and one green. Each of these coincides with the same point. The quality of the image depends on its resolution.
A pixel, commonly, is represented by: 8 bits (28 colors), with 24 bits (224 colors, 8 bits per color channel) or with 48 bits (248 colors); in advanced photography and professional image digitization, even greater depths are used, always expressed in bit values / color channel instead of the sum of the three channels. The first is the most used, reserving the 8-bit for high-quality images but in shades of gray, or with 256 colors in palette selected for low color quality; The 24-bit is the most common and high quality, it is used in most photographic images.