Fair use
In most countries, art and other made-up things, like stories, books, TV shows, and pictures, are owned by the person that first made them. This person can let someone else own the things they make, sometimes for money. The person that owns these things has a copyright for them, which means that person can decide who can copy their work. If someone else copies that work without asking the owner first, that person is breaking the law. The owner can take the person to court and try to get money from them because of what they did.