Espresso has more caffeine (咖啡因） per unit volume than most coffee beverages（饮品）, but because the usual serving size is much smaller, the total caffeine content is less than a mug of standard brewed （煮的）coffee, contrary to a common belief. Although the actual caffeine content of any coffee drink varies by size, bean origin, roast method （烘焙方法）and other factors, the caffeine content of typical servings of espresso vs. drip brew are 120 to 170 mg vs. 150 to 200 mg
Espresso is both a coffee beverage and a brewing method. It is not a specific bean, bean blend（混合咖啡豆）, or roast level. Any bean or roasting level can be used to produce authentic espresso. For example, in southern Italy, a darker roast is generally preferred. Farther north, the trend moves toward slightly lighter roasts, while outside Italy a wide range is popular.
According to the Oxford English Dictionary, the term caffè latte was first used in English in 1867 by William Dean Howells in his essay "Italian Journeys".Kenneth Davids maintains that "…breakfast drinks of this kind have existed in Europe for generations, but the (commercial) caffè version of this drink is an American invention".
The French term café au lait was used in cafés in several countries in western continental Europe from 1900 onward, while the French themselves started using the term café crème for coffee with milk or cream.
In Italian latte (pronounced [ˈlatte]) means "milk"—so ordering a "latte" in Italy will get the customer a glass of milk.
In Italy, caffè latte is almost always prepared at home, for breakfast only. The coffee is brewed with a stovetop moka pot（摩卡壶） and poured into a cup containing heated milk. (Unlike the 'international' latte drink, the milk in the Italian original is generally not foamed（有泡沫的）, and sugar is added by the drinker, if at all).
Outside Italy, a caffè latte is typically prepared in a 240 mL (8 US fl oz) glass or cup with one standard shot of espresso (either single, 30 mL or 1 US fl oz, or double, 60 mL or 2 US fl oz) and filled with steamed milk, with a layer of foamed milk approximately 12 mm (1⁄2 in) thick on the top. In the US, a latte is often heavily sweetened, with 3% or even more sugar.
A flat white is a coffee drink consisting of espresso with microfoam （微泡沫）(steamed milk （蒸牛奶）with small, fine bubbles and a glossy or velvety consistency). It is comparable to a latte, but smaller in volume and with less microfoam, therefore having a higher proportion of coffee to milk, and milk that is more velvety （天鹅绒一样柔软顺滑的）in consistency（浓度） – allowing the espresso to dominate the flavour（口感）, while being supported by the milk.
The coffee style was exported to the United Kingdom by 2005, and by 2010 was being sold in Starbucks franchises there.By 2013 the flat white was available in Australian cafés in New York City, with Hugh Jackman co-owning one of them and endorsing（支持赞助） the product. With the flat white becoming increasingly well known globally, very large coffee shop chains such as Starbucks, Costa Coffee, Caffè Nero and Pret a Manger added flat whites to their menus. Starbucks debuted the flat white in American stores on 6 January 2015。
Outside of Italy, cappuccino is a coffee drink that today is typically composed of double espresso and hot milk, with the surface topped with foamed milk（泡沫奶）. Cappuccinos are most often prepared with an espresso machine. The double espresso is poured into the bottom of the cup, followed by a similar amount of hot milk, which is prepared by heating and texturing the milk using the espresso machine steam wand. The top third of the drink consists of milk foam; this foam can be decorated with artistic drawings made with the same milk, called latte art.
In a traditional cappuccino, as served in Europe and artisan coffee houses in the United States, the total of espresso and milk/foam make up between approximately 150 and 180 ml (5 and 6 imp fl oz; 5 and 6 US fl oz). Commercial coffee restaurant chains in the US more often serve the cappuccino as a 360 ml (13 imp fl oz; 12 US fl oz) drink or larger. In Italy, a cappuccino consists of 25 ml (1 imp fl oz; 1 US fl oz) of espresso; the rest of the cup is filled with equal parts of milk and foam.Outside of Italy, the ratios （比例）of espresso, milk, and foam typically equal 1/3 each.
Cappuccino was traditionally a taste largely appreciated in Europe, Australia, South America, and some of North America. By the mid-1990s, cappuccino was made much more widely available to North Americans, as upscale （高档的）coffee houses sprang up.
In Italy and throughout continental Europe, cappuccino is traditionally consumed in the morning, usually as part of breakfast, often with some kind of pastry（糕点）. Italians generally do not drink cappuccino with meals other than breakfast, although they sometimes drink espresso after dinner.
Caffè macchiato (Italian pronunciation: [kafˈfɛ mmakˈkjaːto]), sometimes called espresso macchiato, is an espresso coffee drink with a small amount of milk, usually foamed. In Italian, macchiato means "stained" or "spotted" so the literal translation of caffè macchiato is "stained coffee", or coffee with a spot of milk.
The caffè macchiato has the highest ratio（比例） of espresso to milk of any drink made with those ingredients（配料）. The intent is that the milk moderates, rather than overwhelms, the taste of the coffee while adding a touch of sweetness. The drink is typically prepared by pouring a small amount of steamed milk directly into a single shot of espresso.One recipe calls for 5–10 g (1–2 teaspoons) of milk heated to 60–66 °C (140–150 °F).