In images, binary is used to store each pixel's colour. This is easy in black and white images, as each pixel is either black or white (1 or 0). However, with more colour depth, more colours become available to use, at the cost of more space being used. The metadata (further information about the data) of an image can include the image size, colour depth, etc. The resolution of an image is how many pixels down and across the image, such as 1920x1080.
Current digital sound is broken down into many different audio samples per second in order to make the audio seem less choppy or broken. But depth is the number of bits available for each clip, while bite rate is the number of bits used per second.