Criminal law deals with "public" wrongs as opposed to disputes between individuals. Governmental bodies, including the federal government, states, and cities, define and prosecute crimes from traffic violations to felonies like rape and murder. The lawyers who represent the governmental bodies in pursuing charges against an individual are called the prosecutors. The lawyers who represent the persons charged with a crime, or the defendants, are called criminal defense attorneys. If you have been charged with a crime, it is essential that you seek legal counsel from an experienced criminal defense attorney at once so that you can preserve your rights and protect your future.
These links will get into more detail about the their respective subjects: