This document defines and describes the properties of real numbers. Real numbers form a set that includes rational numbers like integers, fractions, as well as irrational numbers. Real numbers have two basic operations, addition and multiplication, and follow important properties like closure, commutativity, associativity, distributivity, identity, and inverses. The real number system is hierarchical, with natural numbers at the bottom and real numbers at the top, encompassing rational and irrational numbers.