The set of all integers includes positive integers, 0 and negative integers. According to the new regulations, the set consisting of positive integers and zeros is also called a natural number, usually denoted as n. ..

The commonly used number set and its notation are called positive integer sets, which are denoted as N*, Z+ or n+.

The set of all negative integers is called negative integer set, which is denoted as z-;

The set composed of all nonnegative integers is called nonnegative integer set (or natural number set), and is denoted as n;

The set composed of all integers is called integer set, which is denoted as z;

The set of all rational numbers is called rational number set, and it is recorded as q;

The set composed of all real numbers is called real number set, which is denoted as r;

The set composed of all imaginary numbers is called imaginary number set, which is denoted as I;

The set of complex numbers composed of all real numbers and imaginary numbers is called complex number set, and it is recorded as C.