If you drive around the country long enough, you hear a lot of different acronyms for what is essentially the same thing. In this example, DWI, OWI, and DUI all essentially mean "driving or operating while intoxicated", or drunk driving. However, there may be more than one acronym for the same thing in the same state. For example, one state uses both DUI and DWI for different offenses. Here are some more differences based on various acronyms, what they mean, what they might mean when more than one is used, and some of the legal ramifications if you are arrested in the states that use these different but similar terms:
DWI is "driving while intoxicated"; it means that you drank too much alcohol or consumed alcohol in some other form. You are setting off either the blow meter's readings that the police will test, or that your BAC (blood alcohol content) readings taken from a sample of your blood are higher than the legal limit. These tests often include results of people who have had doses of cold medicine and/or have used mouthwash with alcohol in them, so you should definitely get a DWI attorney on board before you just accept your fate.
OWI is the acronym you might hear a lot in Midwestern states. For example, Wisconsin uses both OWI and DUI, and it is important to note this because they distinguish between "driving while intoxicated" and "driving under the influence". Operating while intoxicated is a much broader description of drunk driving, which also includes operating school buses, city buses, construction vehicles, boats (both private and for profit), RVs, ATVs and UTVs, snowmobiles, and other recreational vehicles.
It means you could be busted for drinking that holiday hot toddy and then taking your new snowmobile out for a spin, so be very mindful of this. If you are busted operating any of the above vehicles, or any other vehicle, the punishment can be quite severe. You will need a lawyer to talk down both the charge and punishment.
Driving under the influence means that you were using alcohol and/or drugs. If it is illegal drugs or the misuse of prescription drugs, that is significantly worse in terms of punishment in many states, especially when those states separate and specify alcohol use under OWI laws from their drug use/abuse laws under DUI. If you are arrested and charged with DUI in states that have separate laws for drug use and operating a vehicle, the punishments include hefty fines in the thousands of dollars and the loss of your license, even if you are just passing through.