Final answer:
The term used in new digital imaging to replace density is 'pixel value', which indicates the relative lightness or darkness of a pixel in a digital image.
Step-by-step explanation:
The term used in the new digital imaging environment to replace density is known as pixel value. In the realm of digital imaging, pixel value corresponds to the relative lightness or darkness of a pixel, which directly influences the brightness and contrast of the image. Digital imaging works by utilizing a matrix of tiny pixels where each pixel records the intensity of light that strikes it, and this is done through a charge-coupled device (CCD). The pixel value is fundamental in determining how light or dark an image appears when displayed on digital devices.