Okay kiddo, have you ever seen those cool-looking angled slats on the outside of some buildings that help block the sun? That's called a "brise soleil" which is a fancy french word that means "sun breaker".
You know how sometimes the sun can be really strong and hot, and make it hard to see or be comfortable outside? Well, the brise soleil is there to help with that. It's like a big shield that blocks the sun's rays and keeps the building cooler inside.
The slats of the brise soleil are usually angled in a way that lets air flow through them, which can help keep the building even cooler. They are also often made of materials that reflect sunlight, so even less heat gets through.
So basically, a brise soleil is a cool-looking shield that helps keep buildings cool and comfortable by blocking the sun's rays. Cool, huh?