Is a jack Russell terrier a species, or all dogs one species?

their not species their called breeds of dogs basically they are for happyness comfort love ,champanionship therapy theses kinda things for also protection species would be like ants, cock roaches salamaders spiders potatoe bugs, lizards, worms, each bug has a job to carry out worms for instance are used for catching fish bees are another form of species humans use them to gain another type of bug fish some are used to feed other animals like snakes breeding is what they do for cats dogs horses cows things like this