What is the image definition of digital camera related to?

Optical zoom is to change the focal length of the lens, which can achieve wide-angle and telescopic effects. Digital zoom is equivalent to taking a big picture and taking a small part of it to achieve the effect of telephoto. The larger the pixel, the larger the printable photo. Image clarity is related to pixel size, CCD (or CMOS) quality, area size, pixel size and lens quality (related to the camera). External reasons include camera stability when shooting, air visibility and so on.