Cinnamon has a warm, sweet flavor and pungent aroma. The taste and scent come from cinnamaldehyde, which makes up most of the essential oil of cinnamon, but also 80 additional aromatic compounds. Cassia has a stronger flavor than the more subtle true cinnamon, which can have floral notes.
Cloves are a spice made from the flower buds of an evergreen tree called, appropriately enough, the clove tree (Syzygium aromaticum). It’s flower buds are harvested in their immature state and then dried & can be used whole or ground, and they have a very strong, pungent flavor and aroma.