As of July 1, 2013 Mississippi passed a law allowing unlicensed open carry. This decision was vacated on August 29, 2013 and is now law. In most areas firearms are still banned in schools, and open carry in public buildings.
Open carry is the ability to carry a gun in plain view. Some states require a permit to open carry, and some do not, but most have restrictions on where it is legal to open carry.