Different types of alcohols have different caloric contents. Dry wines tend to have the fewest calories per serving, while mixed drinks tend to have the most. Unless they also include additional calories in the form of additives like juice, most alcoholic drinks have between 100 and 200 calories.
The calories in alcoholic beverages are what's referred to as empty calories. This means that they have little to nothing in the way of nutritional value. Some types of alcohol, such as wine, have been shown to have health benefits when consumed in moderation, but even these beverages are low on the fats and proteins necessary to maintain a healthy diet.