Espresso
Espresso is a strong black coffee made by forcing steam through dark-roast aromatic coffee beans at high pressure in an espresso machine. A perfectly brewed espresso will have a thick, golden-brown crema (foam) on the surface. If the crema is good, the sugar you add will float on the surface for a couple of seconds before slowly sinking to the bottom.
Espresso is the foundation for a wide variety of specialty coffee drinks, such as the cappuccino, but many aficionados and purists insist that adding anything (besides a bit of sugar) is blasphemy, akin to Scotch lovers mixing their single malt with Coke.
How to have it: Espresso should be taken either on its own or with a small teaspoon of sugar. Having it "short" means that it has less water and is therefore more concentrated, and "long" conversely uses more water and does not taste as strong.
Give it a twist: Adding a dollop of steamed milk creates an espresso macchiato ("macchiato" means stained or marked). Topping an espresso with whipped cream makes it an espresso con panna. Espresso corretto (which translates to "corrected") is made by adding a splash of grappa, cognac or sambuca.