In the United States, the purpose of both criminal and civil law is to punish serious wrongdoings but the way the different courts punish those found guilty in them are different. They also differ in the way charges are initiated, who files suit, how cases are decided, the kinds of penalties that can be imposed, the standards of proof that must be met, and the legal protections that are available to defendants.
There are many offenses that can be tried in both a criminal court as well as in a civil court. An individual or entity can be tried for the same offence in both a criminal court and a civil court.
A common example of an offence that can be tried in both courts is driving while under the influence (DUI). A DUI is a criminal charge that can result in jail time and other criminal punishments. If someone is injured by someone who was driving while under the influence, the victim may file a civil claim seeking monetary compensation against the driver. The outcome of the two cases should not have any bearing on one another. For example, a person may be found innocent in their criminal trial but be found guilty in their civil lawsuit or vice versa, or they may be found guilty or innocent in both cases.