Alcohol, also known as drinking alcohol or ethanol, is the main ingredient in a wide range of social drinks and the reason for the differentiation between “alcoholic” and “nonalcoholic” drinks.
It is a neuroactive chemical that is able to change one's perception, and it has a unique metabolic pattern relative to other sources of calories (the macronutrients; carbohydrates, proteins, and dietary fats). It contributes 7 calories per gram energy-wise, but this does not always correlate well with body weight like the other macronutrients do.