The difference between espresso and coffee basically comes down to how they are brewed. An espresso has to be made in an espresso machine and is made by forcing water through fine, compact coffee grounds thus creating a layer of espresso and a layer of froth. Espresso is stronger and can have a slightly bitter flavor. Coffee is made by pouring water over coffee grounds. Since the water spends more time with the coffee grounds, the grind of the beans is coarser but the end result is a smoother drink.