Special products are referred as such because they follow a pattern.
Sum of squares: (a + b)(a + b) = a² + 2ab + b²
Difference of squares: (a + b)(a - b) = a² - b²
Examples
(x + 3)(x + 3) = x² + 2(3)(x) + 3²
= x² + 6x + 9
(x + 3)(x - 3) = x² - 9
