Difference between print as grayscale and black and white

Question

I was printing something in ubuntu 14.04, and was presented with two options:

1. Print as black and white
2. Print as grayscale

What could be the differences between these two options?

Answer 1

Black and white (monochrome),has only two "colors", black (ink or toner) and white (no ink or toner). It is used for things like text, where you want everything that is a printed character to be black and the background white (unprinted).

Grayscale contains shades of grey and is used for reproducing images. In photographic and similar processes, it is a continuous scale from black to white. On consumer laser and inkjet printers, the printer creates the shades using patterns of micro-dots that generally require magnification to see. These patterns are typically designed to reproduce approximately 256 discrete shades.

On a multi-function printer, say you want to photocopy some text. When you scan the page, the paper and wrinkles will have some color (not pure white), and areas of the text might be faint. If you print that in grayscale, you will get an accurate "photograph" of what the scanner saw. If you want maximum readability, you would use black and white, which would force everything darker than a certain threshold to black and everything else would be white. This will be easier to read and a better representation of how the original came out of the printer.