Product-of-Sums Form

Product-of-Sums Form is a standard way of writing a Boolean Function, where terms built with the OR operator (sums) are combined with the AND operator (product).

For example: $f(x, y, z) = (x + y)(x + z)(y + z)$

It's the dual of the Sum-of-Products Form. To build it from a truth table, you focus on the rows where the function equals 0 instead of 1. See Week 9 - Boolean Algebra A.