In my self-study of Lec.10 of Belyi Maps and Dessins d'Enfants, I came across the following statement
[Right after Remark 7] Let $X$ and $Y$ be Riemann surfaces and $\pi: Y \rightarrow X$ be an unramified covering map of degree $d$...
I understood that an unramified covering map means a covering map without branch points.
And I tried to work out some intuitive example of an unramified covering map of degree d;
- A map being restricted to a domain without branch points, e.g., $y = \sqrt{x}$ on $\mathbb{C} \backslash \{ 0 \} $.
Am I right?