This document discusses different types of real numbers. It defines rational numbers as real numbers that can be written as a ratio of two integers with terminating or repeating decimal representations. Irrational numbers are defined as real numbers that cannot be written as a ratio of two integers, having non-terminating and non-repeating decimal representations. Examples of both rational and irrational numbers are provided. Integers are also discussed as a subset of rational numbers, defined as whole numbers and their opposites.