Illuvium is a make-believe world that exists only in a type of computer program called a blockchain. This world is filled with all sorts of creatures and items that you can collect and use for special purposes. It's kind of like a big game where you get to explore and discover new things.
But, unlike other games, Illuvium is unique because it's built on something called the Ethereum blockchain. This means that everything you find and collect in the game is stored in a special digital wallet that's kept safe on the Ethereum blockchain.
This also means that you can sell the things you've collected, and other people can buy them from you using a special type of digital money called Ethereum. And, because Illuvium is built on the Ethereum blockchain, everything is transparent and secure, so you know that what you're buying or selling is really worth what it says it is.
So, basically, Illuvium is like a magical world in a big computer game that lets you collect rare and valuable things that you can trade with other people using a special digital money called Ethereum.