There are a few different terms that can be used to describe a female dog that has been spayed, or had her reproductive organs removed. The most common term is probably fixed, but you might also hear spayed, neutered, or sterilized. All of these terms mean the same thing: the dog can no longer have puppies.
Spaying or fixing a female dog has many benefits. For one, it helps control the pet population by preventing unplanned litters of puppies. It also eliminates the risk of certain types of cancer and other health problems that can occur in intact (not spayed) females. And finally, it usually leads to better behavior overall, since dogs who are not able to reproduce tend to be less distracted and more focused on their human families.
If you're thinking about having your female dog spayed, talk to your veterinarian about the best time to do so. In most cases, it's recommended that the procedure be done before the dog's first heat cycle (usually around 6 months of age). This reduces the chances of complications and makes for a quicker recovery period post-surgery.