1. The question asks: What is a dog? 2. A dog is a domesticated mammal scientifically known as Canis lupus familiaris. 3. Dogs are known for their loyalty, companionship, and diverse breeds. 4. They are often kept as pets and can perform various roles such as working dogs, therapy animals, and more. 5. This is a general knowledge question rather than a math problem, so no calculations are needed.