Z stands for integer set in mathematics. An integer set is a set of all integers. It includes all positive integers, all negative integers and zeros. In mathematics, integer sets are usually represented by z.

The set of positive integers and 0 is also called a natural number, usually denoted as n, and the set of all positive integers is called a positive integer set, denoted as N*, Z+ or N+. The set of all negative integers is called the set of negative integers, and is denoted as Z-.

Other mathematical symbol sets:

1, r: set of real numbers (including rational numbers and irrational numbers);

2.R+: positive real number set;

3.R-: negative real number set;

4. Q: Rational number set;

5.Q+: positive rational number set;

6.Q-: set of negative rational numbers;

7、? : an empty set (a set without any elements);

8.c: complex set.