Is there a difference?
You may have heard DUI and DWI used interchangeably, but is there a difference between the two? If so what are they?

DUI/DWI what it means
DUI stands for Driving Under the Influence. A DUI offense occurs when someone drives with alcohol in their bloodstream. While the federal legal blood-alcohol content (BAC) limit is 0.08%, some states pursue DUI charges at BAC levels of 0.01%, depending on the driver’s age. An officer can issue a DUI without checking their BAC with a breathalyzer. A DUI can be charged based on erratic driving, the influence of alcohol is suspected, or a field sobriety test.

DWI means Driving While Impaired. In some states a DWI may be defined as Driving While Intoxicated. In these states there is no difference between a DUI and DWI charge. If they are recognized as separate charges, DWI generally refers to driving while impaired by drugs — either prescribed or recreational.

Each of these charges means the driver was exhibiting dangerous behavior while behind the wheel of a car. A driver can be charged with a DUI or DWI after failing a field sobriety test, even with a BAC below the legal limit. Legal outcome depends on the location of the offence, as states with zero-tolerance policies may not differentiate between DUI and DWI violations.

In Missouri
In Missouri there is no legal difference between a DUI and DWI, there is a separate impaired driving classification: DUID. DUID stands for “driving under the influence of drugs,” and can be given if the officer believes the driver is under the influence of any drugs.

( Source: https://www.thezebra.com/dui-vs-dwi/#ms)