Have you ever heard someone say "it's not the dog's fault"? Well, a fault is something that happens that's not the dog's fault - just like how it's not your fault if it starts raining outside.
Let's say you have a dog, and one day you come home to find that your favorite shoes are all chewed up. You might get mad at the dog, but if you think about it, it's really not the dog's fault. Dogs like to chew things, especially if they're bored or don't have anything better to do. So if you left your shoes out where the dog could get to them, it's your fault for not putting them away properly. The dog was just doing what comes naturally to it - chewing things.
Another example of a fault might be if the dog accidentally knocks something over while it's running around the house. Again, it's not really the dog's fault - it's just being a dog. But if you had left something fragile on a wobbly table, that would be your fault for not putting it somewhere safe.
So, a fault is something that happens that's not the dog's fault - it's usually because of something else that's not safe or didn't go as planned. It's important to remember that dogs are just like us - they make mistakes and don't always know what's right or wrong. But if we make sure to keep them safe and teach them good behavior, they'll be great companions for years to come.