Factorization is the process of breaking down a number or an algebraic expression into its constituent parts, called factors. For example, the number 12 can be factored into 3 and 4, since 3 × 4 = 12. In algebra, an expression like x^2 - 9 can be factored into (x - 3)(x + 3), which shows how it can be expressed as a product of simpler expressions. This technique is essential in mathematics, as it simplifies calculations and helps solve equations. Factorization is widely used in various fields, including algebra, calculus, and number theory, making it a fundamental concept in understanding mathematical relationships.