Clarification:
The term "Pixel" stands for "picture element." An image can be represented digitally through various methods. When using RGB pixels, each pixel is defined by three 8-bit binary numbers. Typically, a binary number of 00000000 signifies no presence of the respective color (red, green, or blue), while 11111111 denotes the color at its fullest. The degree of color applied to a pixel corresponds to the binary value.*
A pixel represented by three 8-bit color values is merely a sample of the full image. The extent of the image represented is determined by the resolution, commonly described in terms of the number of pixels horizontally or vertically. For instance, an image might have a width of 4096 pixels and a height of 3072 pixels, translating to roughly 12.6 million samples. Certain coding formats may link a pixel's size to a linear measurement: 160 pixels per inch suggests that the mentioned image would span 25.6 inches wide and 19.2 inches tall. Depending on the device rendering it, a pixel's shape may vary (resolutions can differ in various orientations).
In a camera, light entering is sampled by circuits that detect different colors. The output from these circuits is digitized and processed to ensure that the RGB values for a pixel correlate to the same position in the image.
A rendering device aligns various color-producing methods (registration) to ensure that the red, green, and blue values are accurately combined at the intended spot in the image. There may be additional adjustments considering the color-rendering properties of the device in use. Essentially, this aims to reproduce colors as closely as possible to those captured by the camera in the original scene.
In summary, the pixels in a scene are represented by binary numbers depending on the RGB color components. These binary representations are interpreted by a rendering device (display or printer) to recreate the original colors as effectively as possible.
