Prime factorization is the process of breaking down a number into the prime numbers that can be multiplied together to get the original number. This can be helpful when trying to reduce a fraction because if both the numerator and denominator of a fraction are reduced to their prime factors, you can simply cancel out the prime factors that they have in common.

For example, let's reduce the fraction 18/24:

- The prime factorization of 18 is 2 × 3 × 3.
- The prime factorization of 24 is 2 × 2 × 2 × 3.
- Both 18 and 24 have the one 2 and one 3 in common, so divide them by 6 (the product of 2 × 3).
- The reduced fraction is 3/4.