Okay, so imagine you want a puppy. You go to a store or a website and they have lots of cute puppies for you to choose from. But some people don't want to go to a store or a website, they want to get a puppy from someone who lives near them. That person might be called a backyard breeder.
A backyard breeder is someone who breeds dogs in their backyard, sometimes just to make money. They might not know a lot about breeding or genetics, so their dogs could have health problems. And they might not treat the dogs well, because they're just trying to make a profit.
It's important to remember that not all people who breed dogs in their backyard are bad. But sometimes, they're not doing it the right way. It's always a good idea to do your research and make sure the puppies you're getting are healthy and well-cared for, no matter where they come from.