What is Roasting?
Roasting starts with the bean of the coffee plant. It is dried and becomes green. Once it is in the dry green stage, it is shipped out to roasters around the world. When the roasters receive the beans, they usually come in burlap sacks. The beans must be stored in the proper climate as to ensure their quality.
Roasting the bean takes away much of the acidity and bitterness. Roasting is what makes coffee drinkable.
There is a spectrum of roasts, starting at light roasts and going to dark roasts. The intensity of the roast is how long the bean is roasted for.
As the bean get roasted the sugars in it caramelize. This is what gives it its flavor.