Elevation is the altitude above sea level at which the coffee is grown. The elevation is a good signifier for what you might expect in the coffee in terms of complexity. Put simply, coffee grown at higher altitudes will generally have higher levels of complexity than those grown at lower altitudes. With lower altitude coffees you might expect more nutty, chocolate or earthy notes, whereas higher grown coffee will have brighter acidity and more complexity - expect more floral notes and more layers on the palate.