Real numbers are of two types: Decimal and Integers. The Integers have no decimal values like 0.33, 0.45; Decimals can be 0.23, 0.333… etc

Integers are of three types negative numbers like -1, -2 .. , zero and positive numbers like 1, 2, 3…

The negative numbers and zero are called non positive and zero and positive numbers are called non negative numbers.

Decimal numbers are of finite or terminating decimal types or infinite decimal types. The infinite decimal type is classified as rational numbers if they can be expressed in the form p / q or irrational number if they can’t be expressed in the form p / q.