A rational number is any number that can be expressed as the quotient of two integers, where the denominator is not zero. For example, \( \frac{3}{4} \) and \( -2 \) (which can be written as \( \frac{-2}{1} \)) are rational numbers.

An irrational number, on the other hand, cannot be expressed as a simple fraction of two integers. Its decimal representation goes on forever without repeating.