In a nutshell litho printing uses wet ink and printing plates whilst digital printing uses toners on a press similar to a giant office printer! Digital printing is more suitable for shorter runs and litho printing for longer runs.
The inked image is transferred from a printing plate to a rubber blanket and then the image is transferred again to the paper.
Generally the printing will be done out of the standard four-colour process. This means that the artwork is separated onto four different printing plates and each plate prints a specific single colour – cyan, magenta, yellow and black (CMYK). Together these colours combine to create a full-colour print. Occasionally additional printing plates might also be added to print spot colours.
These may be special inks such as fluorescent or metallic or a specific Pantone ink that matches a corporate colour. Similarly, there might be fewer colours used such as two-colour printing where only two specified colours will be printed, and because only two printing plates are being made this is cheaper than four-colour litho.