Fences are walls put up in fields to prevent animals from wandering or between houses for privacy or security. Types of fences include picket fences, palings, and barbed wire fences. Stone walls are a form of fence popular often found in the Northeast.
Robert Frost wrote a poem called "Mending Wall" in which he questions the idea that "Good fences make good neighbors."
Fences is also the title of a play by August Wilson.