Explanation:
prime numbers is numbers with exactly 2 factors
e.g. 13 = 1×13, the only 2 factors of 13 is 1 and 13, thus, 13 is a prime factor
composite numbers is numbers with more than 2 factors
e.g. 12 = 1×12
= 2×6
= 3×4
the factors of 12 is 1, 2, 3, 4, 6, 12, there is 6 factors, this, 12 is a composite factor