If the discriminant is positive--if b2 -4ac > 0--then the quadratic equation has two solutions.
If the discriminant is zero--if b2 - 4ac = 0--then the quadratic equation has one solution.
If the discriminant is negative--if b2 -4ac < 0--then the quadratic equation has no solutions.

Example: How many solutions does the quadratic equation 2x2 + 5x + 2 have?

a = 2, b = 5, and c = 2.
b2 -4ac = 52 -4(2)(2) = 25 - 16 = 9 > 0.

Thus, the quadratic equation has 2 solutions.