In mathematics, a rational number is any number that can be expressed as the quotient or fraction p/q of two integers, with the denominator q not equal to zero. Since q may be equal to 1, every integer is a rational number.
An integer is a number that can be written without a fractional or decimal component. For example, 21, 4, and ?2048 are integers; 9.75, 5, and ?2 are not integers. The set of integers is a subset of the real numbers, and consists of the natural numbers (0, 1, 2, 3, ...) and the negatives of the non-zero natural numbers (?1, ?2, ?3, ...).
Integers are whole numbers, negative whole numbers, and zero.