Once roasted, all coffee beans look pretty much the same. Even though there are actually dozens of different varieties of coffee beans, when it comes to your coffee cup, only two varieties really matter: arabica and robusta, the two primary coffee types cultivated for drinking.
But what's the difference between the two? Though they might look similar, the two varieties strongly differ in taste, caffeine content, quality, growing conditions and location, price, etc.
Arabica beans tend to have a sweeter and softer taste, with a slight sugar, fruit, and berries taste and it is characterized for their excellent acidity. Robusta, however, has a much stronger taste, with a grain-like and peanut aftertaste.
Caffeine and quality
Robusta beans contain twice as much caffeine as Arabica, and they are generally considered to be of inferior quality. Some robusta, however, are of a high quality and much valued especially in espresso coffees due to their deep flavor and great crema.
Robusta beans are easier to grow. They can grow at lower altitutes than Arabica beans, and they are less vulnerable to pests and weather conditions. They produce fruit much faster than the Arabica type, which might need several years to reach maturity, and they produce more beans per tree.
Coffee beans also differ in their location for cultivation. Robusta is grown primarily in Africa and Indonesia. Arabica is also grown in Africa and Papua New Guinea, but it's mostly grown in Latin America. Colombia only produces Arabica beans. Some countries, like Brazil and India, produce both.
Arabica is a bit pricier. Most coffee shops are exclusively robusta, and instant and cheap ground coffees are mainly robusta. You can still find Arabica in the grocery store. Keep in mind that just because might be labeled Arabica it does not mean it is of higher quality. Ultimately it is all about your personal preferences and taste. Some arabica blends are too high and floral for most tastes. Some of the richest and darkest robusta can be good in a blend. But robusta has twice as much caffeine as arabica, so keep this in mind when choosing a coffee blend.