Integer numbers are integers, i.e. numbers without decimal places or fractions. They are the numbers 0, 1, 2, 3, 4, etc. but also the negative integers -1, -2, -3, etc.
In microprocessor technology, there are integer units that calculate integer instructions. All integer calculations are based on the four basic arithmetic operations and, since they do not take into account any digits after the decimal point, can be performed relatively quickly and also require little memory. If the results contain fractions or decimal places, these are not considered in the further calculation. Example: 9/4 becomes 2 and not 2.25 or 2 1/4.