Integers can be negative numbers. By definition, an integer is a whole number that can be either a positive or negative. Thus, an integer cannot be a fraction, percentage or decimal.
Numbers are divided and classified by types. Like integers, natural and whole numbers are also types of numbers. Natural numbers, sometimes called counting numbers, are used for counting and ordering objects. They are the first numbers children learn in school. They begin with one and span as far as a person can count. Whole numbers include all natural numbers in addition to zero and, like natural numbers, are always positive.
Written out, integers look like: "..., -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, ..." Similar sets of numbers are whole numbers, which are integers from 0 and up (0, 1, 2, 3, 4, ...), and counting numbers, which are integers from 1 and up (1, 2, 3, 4, 5, ...). Fractional, or decimal numbers may not be integers. For example, 1/2 or 0.5 is not an integer, though 2/1 or 4/2 is actually 2, which is an integer.