Assault and battery are two unlawful acts that often occur together. Assault is the act of making a threat or otherwise intimidating a person to create the belief that physical harm or unwanted contact will be done immediately to him or her. Battery is the act of actually harming someone physically, or touching them in a way that is offensive.
Assault and battery can be both serious and lead to significant punishments. Battery is the more serious of the two, however, and can be accompanied by longer and more severe sentences. People can get very injured from battery. For example, if two people start beating one another on the street, this would be battery, and it could result in severe injuries. Such an incident could be accompanied by assault (if threats were made), or the battery could take place on its own.