What is the difference between Spot and Process colors?

Spot colors are printed with a single solid color, using a specially mixed Pantone color ink. Spot colors are used to maintain color consistency throughout a design.

Process colors are printed using varying percentages of Cyan, Magenta, Yellow, and Black inks, to reproduce colors. Black in CMYK is referred to as K, indicating “key” for the printing term key plate. A key plate impresses the artistic detail of an image, usually in black ink. By mixing the CMYK colors together at various levels you can achieve different shades and colors within a design.