This question is addressing the discrimianant (The number in the square root of quadratic formulas). Real roots are when the discrimanent isn't imaginary. This means that you can't have a negative under the radical. Unequal means that the discrimanent can't equal zero b/c + or -0 will get you roots that are equal. Irrational means that it is a fraction. This means the discriminant cannot be a perfect square.
Irrational numbers are not 'fractions'. A rational number is a number that can be written as p/q, where p and q are both integers. An irrational number is any other real number besides those. Examples include pi, e, and any non-perfect square root.
An "irrational number" means that the number never ends and there is never a repeating pattern of numbers. For example 1/9=.111111 and it never ends, however there is a repeating pattern of 1 therefore it is rational. Square roots of non perfect squares are always irrational i.e. radical 2.