The term Notes or Cupping Notes are the subtle flavors that a coffee bean presents when tasting a cup that is brewed using the described beans.
The idea is that as you are tasting the coffee, that you can detect a hint of the described flavor (or Note). For example, when a coffee bean is described has having chocolate cupping notes, that means that as you drink a cup, you can taste a hint of chocolate flavor.
Some confuse a Note meaning that the coffee bean is artificially flavored with whatever the Note describes. However, typically the true Note often comes from having the coffee bean grown near other crops. The nearby crops will have their strong odor proliferate the coffee bean as it’s growing.
For example, if a coffee bean is farmed under orange, lemon and/or lime trees, that coffee bean might exhibit a citrus cupping note. If a coffee bean is farmed near a pepper farm, it might exhibit a spicy cupping note.