In algebra, the zero-product property states that the product of two nonzero elements is nonzero. In other words, ${\displaystyle {\text{if }}ab=0,{\text{ then }}a=0{\text{ or }}b=0.}$

This property is also known as the rule of zero product, the null factor law, the multiplication property of zero, the nonexistence of nontrivial zero divisors, or one of the two zero-factor properties. All of the number systems studied in elementary mathematics — the integers ${\displaystyle \mathbb {Z} }$, the rational numbers ${\displaystyle \mathbb {Q} }$, the real numbers ${\displaystyle \mathbb {R} }$, and the complex numbers ${\displaystyle \mathbb {C} }$ — satisfy the zero-product property. In general, a ring which satisfies the zero-product property is called a domain.