A real number is a type of numerical quantity that encompasses all rational and irrational numbers. Real numbers are located on the real number line, which extends infinitely in both directions.
They include integers (whole numbers), fractions (rational numbers), and numbers with infinite decimal expansions (irrational numbers) like π (pi) and √2 (square root of 2).
Real numbers can be positive, negative, or zero and are used in various mathematical and scientific contexts to represent quantities, measurements, and values in the real world.