Modulo

A mathematical operation, defined as the remains after an integer division.

Ex.

10/7=1, 10mod7=3 (10-1*7=3)

42/9=4 42mod9=6 (42-4*9=6)

In image processing, to say that a resoluion is mod-n means that the resolution is exactly dividable with n, i.e. res mod n = 0