Number types are classifications of numbers based on their properties. The main types include natural numbers, which are the counting numbers starting from 1; whole numbers, which include natural numbers and 0; and integers, which encompass positive and negative whole numbers. Additionally, there are rational numbers, which can be expressed as a fraction of two integers, and irrational numbers, which cannot be written as a simple fraction, such as π or the square root of 2. Lastly, real numbers include all rational and irrational numbers, while complex numbers consist of a real part and an imaginary part.