Oud, also known as agarwood, is a highly valued aromatic resin that forms in the heartwood of aquilaria trees when they become infected with a type of mold. This resinous wood develops a complex, deep scent as it reacts to the fungal invasion, and is eventually harvested for its distinctive fragrance. The scent profile of oud is rich and multifaceted, characterized by a deep, woody base with notes that can range from sweet, smoky, and warm to earthy, musky, and balsamic. Its overall aroma is often described as profoundly exotic and lingering, making it a prized ingredient in the perfume industry for its longevity and intensity. Oud's powerful, mystique-filled aroma provides a luxurious and enigmatic backdrop to many high-end and niche fragrances, appealing to those seeking a unique and compelling scent.