Original: In mathematics, two integers a and b are said to be coprime (also spelled co-prime) or relatively prime if they have no common positive divisor other than 1 or, equivalently, if their greatest common divisor is 1. The notation a b is sometimes used to indicate that a and b are relatively prime.
Simplified: In mathematics, two integers (a and b) are coprime (or relatively prime) if they share no common factors.