Arábica vs Robusta
Coffea, the coffee plant, is a flowering tree that produces small red or purple fruit called cherries.
According to the National Coffee Association, a single coffee tree produces about 10 pounds of coffee cherries a year, which equals about 2 pounds of green coffee beans.
A few species of coffee plants grow in the wild, but the most important ones are: Coffeea arabica and Coffeea canephora (well known as robusta). Most of commercial coffee grown, around 70 or 80 percent, is arabica. But what are the main difference between those two species:
Robusta was discovered in the Belgian Congo in the late 19th century. It is able to grow and fruit at lower altitudes than the existing Arabica plants. Also, Robusta is cheaper to produce and more resistant to disease.
Another quality about Robusta is that it has a woody, burnt-rubber quality in the cup. It usually has very little acidity, but will have a heavy body and mouthfeel.
Currently most of the Robusta produced around the world ends up in large manufacturing plants destined to become instant soluble coffee.
Also, Robusta has about twice the content of caffeine than Arabica.

However, Arabica is of distinctly higher quality than robusta, but some people say that well roasted Robusta is much better than a poor Arabica.
High quality Arabica coffee should have a slightly sweet flavor with hints of chocolate, caramel and nuts, and also some fruits and berries taste.
Nevertheless, there is a lot of Arabica types and the most known are: Caturra, Bourbon, Typica, Catuai and Gesha.
So, from now on you have an idea of which coffee to get and how arabica or robusta could affect the taste of coffee in your cup.