Let's start at the beginning. Espresso, also referred to as caffe espresso, is a way of making coffee. It is created by filtering pressurized hot water through tightly packed and finely ground coffee beans. The end result is usually more "syrupy" than normal coffee but has the same flavor and caffeine as your typical morning cup o' joe. Espresso is often added to macchiatos, lattes and cappuccinos to increase the caffeine in each drink.
And so you may be asking yourself, is there such thing as an "Espresso Bean"? In short, no. Espressos can actually be made of any type of coffee bean. In fact, any bean sold as ideal for use in espresso machines is just being marketed differently!
Many people are surprised to find out that coffee beans are naturally green when harvested. It is through roasting that an untouched coffee bean is transformed into the flavorful bean connoisseurs love. Unroasted coffee beans have a unique flavor depending on their origin country. It is during the roasting process that the beans slowly lose their original flavor and gain a roasted one. The darker the bean, the harder it is to taste the original flavor.
So which bean is best for your espresso? It's up to you! If you have access to a grinder, the only limits are what beans are available to you and your own imagination.