Question

What are rational and irrational numbers ?

Answer 1

Anything rational can be expressed in a form other than a symbol. However, irrational numbers are those that go on forever and never stops, such as $\pi$ or phi

Answer 2

Rational: Any number that can be expressed as a fraction (or a ratio.)
Irrational: Not rational, any number that can't be written down as a fraction. Some examples include $\pi (3.1415926...)$, $\sqrt{2}$, and so on.