Criminal law is designed to protect people in our society from the wrong doing of others.  Criminal activities that occur most frequently and carry the highest penalty of the law are: murder and rape, which are felonies.  Also, there are misdemeanors, such as drunkenness, reckless driving, etc.  Misdemeanors are the less harsh of the two types of criminal law.  If you are being prosecuted for a misdemeanor or a felony, you must get the best lawyer possible.  If you can afford one, the state will appoint one to you to defend you.