For questions about the set of integers, or positive and negative whole numbers, commonly denoted $\mathbb{Z}$.

The integers are the whole numbers, positive, negative and zero. That is, the integers are the numbers that appear in the infinite list

$$.\quad .\quad .\quad -5\quad -4\quad -3\quad -2\quad -1\quad 0\quad 1\quad 2\quad 3\quad 4\quad 5\quad .\quad .\quad .\quad$$

The set of all integers is denoted by $\mathbb{Z}$. The letter Z comes from the German word "Zahlen" which means "numbers". The integers are related to many other familiar sets of numbers:

$$\mathbb{N} \subset \mathbb{Z} \subset \mathbb{Q} \subset \mathbb{R} \subset \mathbb{C}.$$

The set of integers are closed under addition, subtraction, and multiplication. Together with the additive identity $0$ and the multiplicative identity $1$, the integers form an example of a commutative ring with unity. In fact, it is a Euclidean domain.