Positive integers are whole numbers greater than zero. They include numbers like 1, 2, 3, and so on, extending infinitely. Positive integers do not include fractions, decimals, or negative numbers. They are often used in counting and ordering. In mathematics, positive integers are part of the number system known as natural numbers. They play a crucial role in various mathematical concepts, including arithmetic, number theory, and combinatorics. Positive integers are essential for basic calculations and are foundational in understanding more complex mathematical ideas.