Arabica and Robusta are the two kinds of coffee beans used in commercial coffee production. The main differences between them are their taste and where they are grown. When it comes to their difference in caffeine level, Robusta beans contain twice the level of caffeine than Arabica beans. Arabica beans have a milder, more aromatic taste while Robusta beans hold a stronger, more acquired flavor. Arabica beans are flat and oval in shape while Robusta beans have a more obvious round shape. When they are still on their plant, the beans can easily be told apart by their difference in colour as Arabica beans are a darker shade of green then Robusta beans. 
Arabica beans are cultivated in Central and South America due to the subtropical climates as they can only be grown in places with higher climates. Robusta beans on the other hand, are cultivated in Central and West Africa and South East Asia, as they require places with little rainfall and lower altitudes to grow. Over 70% of the coffee grown around the world is Arabica and is generally known as the higher quality bean. Robusta coffee is characterised by its woody and earthy flavours. You most likely won't see a 100% Robusta blend on the market, as Robusta is naturally higher in caffeine and is to strong to drink. However, there are many high quality blends of Robusta available on the market, which provide great flavours once mixed with Arabica beans.
Arabica Beans
· Grown at high altitudes above 800m
· Grown in places with higher climates
· Mild, well balanced in flavour
· More expensive coffee bean
· Naturally lower in caffeine
Robusta Beans
· Commonly used in instant coffee
· Grown at lower altitudes between 200m-800m
· Grown in places with lower climates
· More astringent and bitter in flavour
· Has twice the amount of caffeine than Arabica beans
