User: What are 3 differences between the arabica and robusta species of coffee?
Assistant: First, robusta is considered to be more bitter and less flavorful than arabica. Second, robusta contains 40-50% more caffeine that arabica. Third, because of the higher bitterness and less flavorful quality of robusta, about 75% of all coffee cultivated in the world is arabica making it much more popular than robusta.