Base notes are the final and longest-lasting scents in a fragrance. They typically emerge after the initial top and middle notes have evaporated, providing depth and richness to the overall scent. Common base notes include vanilla, amber, and musk, which can linger on the skin for hours or even days. These notes are essential in creating a well-rounded perfume, as they help to anchor the lighter top and middle notes. Base notes contribute to the fragrance's overall character and can evoke emotions or memories, making them a crucial element in the art of perfumery.