Exclusively speaking, there are 2 main types of coffee species: Arabica and Robusta. While Arabica beans contain less caffeine content, they are sweet and have a good amount of lipids as compared to Robusta. The Arabica crop is chemically complex; so many companies find it innovative to use them for their best coffee beans.
On the other hand, Robusta is generally grown at higher altitudes and used to make instant coffee. It has higher caffeine punch than Arabica and is quite tough in taste.