Espresso is coffee brewed by forcing a small amount of nearly boiling water under pressure through finely ground coffee beans.
Drip brewing, filtered coffee, or pour-over is a method which involves pouring water over roasted, ground coffee beans contained in a filter, creating the beverage called coffee.
Decaf is short for decaffeinated coffee. It is coffee from coffee beans that have had at least 97% of their caffeine removed. There are many ways to remove caffeine from coffee beans. Most of them include water, organic solvents or carbon dioxide.