A coffee bean is a seed of the Coffea plant and the source for coffee. It is the pip inside the red or purple fruit often referred to as a coffee cherry. Just like ordinary cherries, the coffee fruit is also a so-called stone fruit. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans.
The two most economically important varieties of coffee plant are the Arabica and the Robusta; approximately 60% of the coffee produced worldwide is Arabica and ~40% is Robusta. Arabica beans consist of 0.8–1.4% caffeine and Robusta beans consist of 1.7–4.0% caffeine.