What is Vapor moves to the cooler end?

Vapor moves to the cooler end because it wants to be comfortable, just like you when you move from a hot room to a cool one.

Imagine you're playing with a balloon on a sunny day, it's full of air and feels nice and warm. Now, if you take that balloon into the fridge, what happens? The air inside gets cooler, and the balloon starts to shrink. That’s because the vapor (like the air in the balloon) moves where it’s more comfortable, to the cooler place.

Think of vapor like a group of little friends who are always moving around. When they’re warm, they move faster and spread out more. But when they find a cooler spot, they slow down and crowd together. That's why you see things like condensation, like when your glass gets wet on a hot day. The vapor in the air moves to the cooler part of the glass and turns back into liquid.

So, whether it’s inside your balloon or on your glass, vapor always takes the path to the coolest place, because that’s where it feels most at home!