What are integers?

Integers are a type of number. The set of integers includes all natural numbers such as +1, +2, +3, and so on. And integers include all negative natural numbers such as -1, -2, -3, -4, ......and so on. Plus integers include the number zero.

So an integer is any number contained in the set of numbers {...-3, -2, 1, 0, 1, 2, 3, ... }

Is +100 an integer? Yes.
Is - 234 an integer? Yes.
Is  1.25 an integer? No, since the number 1.25 is not one of the numbers in the set of integers.

Enjoy.