Black and White and monochrome are terms which are frequently used as synonyms for describing a photo which contains only black, white and shades of gray rather than full color.However,there are some major differences between these terms.
Black & White…….The description black and white can be misleading as the resulting photo is rarely made of solely black or white pixels.Instead the photo usually contains pixels which vary from black through many shades of gray to white.
Monochrome…..The term monochrome refers to a photo having one color(mono meaning one and chrome meaning color).It is frequently used to describe a black and white photo but it also describes photos which contain a single tone, such as sepia or rose tint.
So the picture above can be called Black and white or Monochrome
These two photos can be also be called monochrome,The one on left is cyan, the one on right is sepia.
I will have more on this subject in another blog, Thanks