how do you tell if a dog is a street dog "breed"?

[Ken S]

i have a neighbour who barley takes care of the dog cause he has work to do and comes back late, and his labourer(i wouldnt say labourer) is too busy cleaning the house so at night so i take the puppy for a walk sometimes. I'm wondering how do i know if this dog is a street dog type... because it sort of looks like a labrador puppy but in a way it looks like its a street dog. how do i compare out the difference....im just wondering ^^