Labradors were bred to be hunting and fishing dogs in what is now Newfoundland, Canada. They are capable at these tasks (hence the name retriever) and often assist humans on hunting trips in multiple parts of the world.
As domesticated animals, the Labradors habitat is usually a humans home where they gorge on whatever falls on the floor and perform tricks in exchange for puppy treats. They are very loving dogs and do best with human companionship. With care, they are able to live in all the same environments humans do. There are several mix breeds including the Labradoodle (pictured above).
Further information about Labrador Retrievers is available at the following at the Labradors wikipedia article and on the index page.