How does the Difference blend mode work in Adobe Illustrator?

Question

Adobe Illustrator

Why does white on white produce black, but black on black produces nothing?
On what example can you clearly understand the principle of operation of this blending mode?

Answer 1

Difference - Difference. Difference in mathematics is the result of subtracting one from the other.
255 - 255 = 0 (black)
0 - 0 = 0 (black)
Layer blending modes are, roughly speaking, mathematical operations with numerical color parameters.