What Is An Americano?
An Americano is an espresso that has been diluted with water to make it weaker. An Americano is usually the same size as a cup of coffee (8 ounces), which means it is roughly 7 ounces of hot water and 1 ounce of espresso. It's still roughly as strong as a regular coffee because of how concentrated espresso is, though it only contains as much caffeine as an espresso (usually 30mg-45mg).
The term originates from WW2, where American soldiers would dilute the espresso that was widely available as a substitute for coffee, which was not available.
Coffee shops whose standard drinks are more than 8-oz (Starbucks for example has 12-oz and 16-oz drinks) will add additional shots of espresso to keep their Americano from diluting too much. This obviously increases the quantity of caffeine as well. Americanos can have the same dairy and flavouring products added to it is a coffee, to match peoples' individual tastes. Milk or cream may be used to soften the flavour, while sugar or flavoured syrups may be introduced to add a unique twist.
Americanos differ from lattes in the sense that they're primarily composed of water, whereas lattes are formed using steamed milk. This makes Americanos more bitter tasting than hand-crafted dairy-based beverages.