Black and white printing of an image could be done as one-color process printing and four color process printing.
When one-color process printing is used for the black and white image, it prints with one plate with black color and could be done on the one color press.
For the more reach look of the b&w image four color process could be used (also known as CMYK). Color printing involves a series of steps in order to generate a quality black and white reproduction and it similar to four color printing of the color image.