You know how sometimes people build really big walls made of cement near rivers or lakes to stop the water from flowing? This is called a dam. Well, sometimes people build dams that are really, really big and they can affect a lot of things like the environment, the people who live nearby, and other countries that share the same river.
That's where the International Commission on Large Dams comes in. It's like a group of grown-ups who come together from different countries to talk about these big dams and figure out ways to make sure they are built safely and don't cause problems for people and the environment.
They look at a lot of things like how strong the dam is, how much water it can hold back, and how it might impact the wildlife and plants around it. They also talk to the people who will be affected by the dam and try to figure out how to reduce any negative effects on them.
So, the International Commission on Large Dams is like a team of really smart grown-ups who want to make sure big dams are built in a way that's good for everyone and the planet.