Imagine a big group of stars in the sky, like a family of stars that live together in the same neighborhood. That's what a cluster is: a group of stars that are close to each other because they formed from the same cloud of gas and dust.
The Fornax Cluster is a special group of stars because it's really far away in space, much farther than you can see with your eyes. It's like a family of stars that live very far away from us, but we can still study and learn about them. Scientists use telescopes to look at the Fornax Cluster and learn more about the stars that live there.
The Fornax Cluster is also special because it has a lot of galaxies in it. Remember that galaxies are like big families of stars, with lots of stars and gas and dust and planets all living together. The Fornax Cluster has hundreds of galaxies in it, all orbiting around each other like a big dance party in space.
Scientists study the Fornax Cluster to learn more about how galaxies form and evolve over time, and how stars and planets are born and grow up. It's a really important place to study because it can teach us a lot about the universe we live in, even though it's so far away.