Espresso is coffee brewed by forcing a small amount of nearly boiling water under pressure through finely ground coffee beans. Espresso is generally thicker than coffee brewed by other methods, has a higher concentration of suspended and dissolved solids, and has crema on top (a foam with a creamy consistency).
As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated. Espresso is also the base for other drinks such as a caffè latte, cappuccino, caffè macchiato, caffè mocha, flat white, or caffè Americano.