A wholenumber is a number without fractions; a positive integer or 0.
An integer is colloquially defined as a number that can be written without a fractional component. For example, 21, 4, 0, and −2048 are integers.
Irrational numberis any real number that cannot be expressed as the quotient of two integers. For example, there is no number among integers and fractions that equals the square root of 2.