Numbers can be categorized into several types based on their properties. The main types include natural numbers, which are the counting numbers starting from 1, and whole numbers, which include all natural numbers plus 0. Integers extend this set to include negative numbers, while rational numbers consist of fractions formed by dividing integers. Another important category is irrational numbers, which cannot be expressed as simple fractions, such as the square root of 2 or pi. Lastly, real numbers encompass all rational and irrational numbers, while complex numbers include a real part and an imaginary part, represented as a + bi, where i is the imaginary unit.