Okay kiddo, let's talk about blowholes in geology. Have you ever seen a big wave crash against a rocky shore? It makes a lot of noise and water sprays everywhere, right? Well, sometimes when the waves crash against the rocks, they make small holes or cracks.
Over time, the waves keep hitting these cracks, and the pressure starts to build up inside them. Eventually, the pressure can get so high that it shoots a fountain of water and air out of the hole - just like when you blow air through a straw! This is what we call a blowhole.
Blowholes can be different shapes and sizes, but they all have one thing in common: they're caused by the power of the waves. Some blowholes can shoot water up to 30 feet in the air! People love to watch blowholes because they're really cool and can make a big splash.
So, in short, a blowhole is a hole or crack in the rock made by waves, which creates pressure inside and shoots out water and air like a big fountain.