Really strong coffee served in a teeny tiny cup, meant to be drank in little sips or in one big gulp like a shot. Is also used to make Americano (or a normal coffee) by adding water, or a Cappucino or Latte by adding hot milk and froth, or a Mocha by adding chocolate powder, milk and froth.
Most coffee shops put 2 shots of espresso in any coffee, so if you like your coffee strong, ask for an extra shot, if you like it weak, ask for one less.
Louise is such a wimp, she drinks grande latte's with only one shot of espresso. It's hardly worth it!