Oak smells like a rich, deep, and slightly smoky wood scent. It's earthy and grounded, with a dry, almost nutty quality that feels solid and mature. Some people also pick up a subtle vanilla or spice undertone depending on how it's used. Oak smells like the warm, comforting smell of a bonfire crackling outside or the inside of a nice wooden-paneled room. It's used in fragrances as a base note to add strength, depth, and a rugged, natural quality.