An alcoholic drink is a drink that contains 0.5% or more ethanol. In chemistry there is a whole class of substances known as alcohols. The alcohol used in alcoholic drinks is known as ethanol or "grain alcohol". Grain alcohol is generally made through a process called fermentation. In fermentation, bacteria change sugar to make ethanol or vinegar. Other kinds of alcohol are usually harmful to drink, so the only kind of alcohol used in alcoholic drinks is grain alcohol. Since most people do not have to use any other kind of alcohol except ethanol, they will use the word "alcohol" to mean only ethanol. Sometimes people also use the word "alcohol" to talk about any drink containing ethanol, such as whiskey, vodka, or gin.