The very large hadron collider (LHC) is a big machine that scientists use to study tiny particles called atoms. It's kind of like a really big microscope, but instead of using light to look at things, it uses tiny particles called protons.
The LHC is made up of a big loop called a tunnel, where the protons race around really fast. They go so fast that they smash into each other, like two cars crashing. When the protons smash into each other, they create lots of other tiny particles that scientists can study.
By looking at these tiny particles, scientists can learn more about how atoms work and what they are made of. They can also learn about things like how the universe was created and what it is made of.
The LHC is really big and complicated, and it took lots of smart scientists many years to build. But it's a very important tool for learning more about the world around us!