Think of it like a small, round opening on the very top of their head. This blowhole allows them to breathe air while swimming at the surface, and it also helps them to communicate with each other through whistles and clicks.
Where is the blowhole on a dolphin?
Dolphins don't have a "blowhole" in the same way humans have a nose. They have a single blowhole located on top of their head, which acts as both their nose and their breathing apparatus.