From way back in 3rd grade...

3 * 2 = 6 ... 3 and 2 are the factors of 6 ... 6 is the product

It works the same way with messier factors...

2 ( w^3 ) ( y^4 ) ( z ) ... these are factors


2x ( 3y + 5 ) = 6xy + 10x ... 2x and ( 3y + 5 ) are the factors


( x - 3 ) ( x + 7 ) = x^2 + 4x - 21 ... ( x - 3 ) and ( x + 7 ) are the factors


( 5x - 1 ) ( 2x + 3 ) = 10x^2 + 13x - 3 ... ( 5x - 1 ) and ( 2x + 3 ) are the factors


( x - 1 ) ( x^2 + x + 1 ) = x^3 - 1 ... ( x - 1 ) and ( x^2 + x + 1 ) are the factors