There are lots of different types of dogs. Every breed of dogs are unique.
There are dogs such as adult dogs and puppies or pups such as baby dogs.
Some dogs are big and some are small. Some dogs can be the size of a average adult and some can fit in a teacup, those are know as teacup dogs.
Dogs can be calming, jumpy, and some dogs will run with you or guard your house.
Dogs can be used to help you and others. They can pull things and even hold things. But when they hold things, its with there mouth.