Think back to your fourth grade arithmetic When you divide two numbers, you have a dividend (the number on top), a divisor (the number on the bottom), a quotient (the answer), and a remainder (what's left over) In computer science, this kind of division is very important However, we're usually more interested in the remainder than in the quotient When we're interested in the remainder, we call the operation a modulus (or modulo, or mod) For instance, one of the examples on your fourth grade arithmetic text might have been 13 ÷ 3 = 4 (with a remainder of 1) As computer users, we're more interested in 13 mod 3 = 1 It's really the same operation, though Modulo is also used in expressions like "modulo wildcards," which means "everything but wildcards "
The modulo or remainder operator returns the remainder from long division Contrast this with integer division which returns the quotient from long division
the operation or function that returns the remainder of one number divided by another
The number that indicates the number of groups in a file Typically, talking about choosing modulo is a good way to start a heated argument in a room full of technical types