In perfumery, fragrances are composed of different layers of scents called notes, categorized into top, middle and base notes. Top Note: Definition: The initial scent you perceive immediately after applying the fragrance. Characteristics: Light, fresh, and often volatile, top notes are designed to make a strong first impression. Middle Note: Definition: Also known as the heart note, it emerges once the top note dissipates and forms the core of the fragrance. Characteristics: More rounded and well-balanced, these notes often provide the main theme of the scent and last longer than the top notes. Base Note: Definition: The final layer that appears once the top and middle notes have evaporated. Characteristics: Rich, deep, and long-lasting, base notes provide the foundation and depth to the fragrance, often lingering for hours.