A real number is a value that can represent any continuous quantity, positive or negative. Real numbers include integers, rational numbers, and irrational numbers. The adjective real applied to the idea of number is to distinguish the real numbers from complex numbers, which can represent values which do not correspond to the points on a single line.
Real numbers correspond one-to-one with the points on an infinite line, and that correspondence produces the real number line.
Main article: Properties of Real Numbers
The real numbers follow many of the same properties as integers, and in particular, can be operated upon using the commutative property of addition and multiplication, the associative property of addition and multiplication, and the distributive property.