Within the Coffea genus, there are four main species of coffee beans. The most common and economically relevant are Arabica and Robusta coffee beans, which account for more than 90% of global coffee production. The other types of coffee beans grown commercially are Liberica and Excelsa. Arabica and Robusta are the two most common types of coffee sold and produced in the world today.
But even though they're so common, most people have no idea what the difference is between them. When it comes to global production, Robusta coffee beans are second on the list and the most popular in Europe, the Middle East and Africa. It has a much fruitier character than Liberica, with an acidic acidity that makes it popular for adding complexity to coffee blends. Liberica trees grow much taller than Robusta or Arabica, and the coffee beans in these trees are larger and have a more irregular shape.
Although the Coffea liberica plant originated in West Africa, it is mainly cultivated in Malaysia and the Philippines. This information is certainly useful in identifying what to expect from a given coffee, but it doesn't tell the whole story. The Arabica coffee species is particularly prone to disease, so growing it in large quantities is a challenge. It's not everyone's cup of tea, but there are some exceptional Liberica coffees that can be enjoyed when they are well prepared.
As mentioned before, Arabica is the most common (and certainly the most commercialized) type of coffee in North America. This decision greatly helped the Philippine economy, as they were the only supplier of coffee for a time. Liberica beans are larger than others, often asymmetrical, and are the only coffee beans in the world that have such an irregular shape. We've said it before and we'll say it again, drinking coffee is all about finding what you like and getting on with it.
Like the Liberica coffee described above, Excelsa is mainly grown in Southeast Asia and represents only a small fraction of the world's coffee production. You're probably already familiar with this commonly produced coffee bean; it accounts for more than 60% of the world's coffee production. Ultimately, this led to the fall of the Liberica coffee bean in the world market, as no other country could match the production in which the Philippines had pioneered.