This document discusses the nature of roots of quadratic equations based on the discriminant. It defines the discriminant as the number used to describe the nature of roots, with the formula d = b^2 - 4ac. It then outlines the nature of roots for different values of the discriminant: if d > 0 the roots are two real and unequal, if d = 0 the root is one real, and if d < 0 there are no real roots. It provides examples of finding the discriminant and describing the nature of roots for quadratic equations.