0 (zero) is both a number and the numerical digit used to represent that number in numerals. It plays a central role in mathematics as the additive identity of the integers, real numbers, and many other algebraic structures. As a digit, zero is used as a placeholder in place value systems. Historically, it was the most recent digit to come into use. In the English language, zero may also be called null or nil when a number, "oh" () or cipher (archaic) when a numeral, and nought or naught in either context.
0 as a number
0 is the integer between 1 and −1. In most systems, 0 was identified before the idea of 'negative integers' was accepted. Zero is an even number.Lemma B.2.2, The integer 0 is even and is not odd, in Zero is a number which quantifies a count or an amount of null size; that is, if the number of your brothers is zero, that means the same thing as having no brothers, and if something has a weight of zero, it has no weight. If the difference between the numb