While a DWI refers to driving while impaired or intoxicated, a DUI refers to driving under the influence. Depending on the state in which you were pulled over, a DUI and DWI can refer to the same offense or have two different meanings. A DUI and DWI can both mean a driver is being charged with a serious offense that endangers others. Both can apply to alcohol and other drugs that impair driving ability. While some states refer to drunken or impaired driving as either a DUI or DWI, others use both terms. Often, one term will refer to impairment by substances other than alcohol, while the other refers to alcohol exclusively. The words’ meanings can also flip-flop from state to state.