An assault charge can come in one of four degrees, with "first degree" being the most serious and "fourth degree" being the least. Whether you are being charged with first or fourth degree assault, it is extremely important you take the charges seriously. A criminal conviction of violence will cause you serious problems in the future, whether it be with getting a job or finding a place to live.
First degree assault through third degree assauts are felonies. First degree assault in a class A felony which means the maximum penalty is potentially up to life in prison and a $50,000 fine. Second degree assault is a class B felony which means the maximum penalty is 10 years in prison and a $20,000 fine. Finally, third degree assault is a class C felony which means the maximum penalty is five years in prison and a $10,000 fine.
Fourth degree assault, instead is a gross misdemeanor, which means the maximum penalty is 364 days in jail and a $5,000 fine. A conviction will also often come with probation, a no contact order, and maybe court ordered classes.
Whether you get charged with first degree or fourth assault depends on the facts of your case. This includes whether weapons were involved, whether there were serious injuries (or the potential for serious injuries), who the victim was, along with the intent.