What does $\mathbb{C} / \mathbb{Z}$ mean?

Question

In the following question I need to use $\mathbb{C} / \mathbb{Z}$ :

Prove that $\mathbb{C} / \mathbb{Z}$ is isomorphic to the multiplicative group $(\mathbb{C}^*,\cdot, 1)$.

But what does $\mathbb{C} / \mathbb{Z}$ mean? I understand things like $\mathbb{Z}/N\mathbb{Z}$, but cannot grasp $\mathbb{C}/\mathbb{Z}$ . Thanks!

Answer 1

$\mathbb{Z}$ is a subgroup of the additive group of $\mathbb{C}$, so you can take the quotient $\mathbb{C}/\mathbb{Z}$.

Answer 2

$\mathbb C/\mathbb Z$ is a cylinder.