An integer is a whole number that can be positive, negative, or zero. Integers do not include fractions or decimals, making them a fundamental part of mathematics. Examples of integers are -3, 0, and 7. They are often used in counting, ordering, and various mathematical operations. In mathematics, integers are part of the set of numbers known as the real numbers, which also includes rational and irrational numbers. The set of integers is usually denoted by the symbol ℤ, which comes from the German word "Zahlen," meaning "numbers." Integers play a crucial role in algebra, number theory, and many other areas of math.