Agarwood or aloeswood is a fragrant dark resinous wood used in incense, perfume, and small carvings. It is formed in the heartwood of aquilaria trees when they become infected with a type[which?] of mould. Prior to infection, the heartwood is odourless, relatively light and pale coloured; however, as the infection progresses, the tree produces a dark aromatic resin, called aloes or agar (as well as gaharu, jinko, oud, or oodh; not to be confused with bukhoor), in response to the attack, which results in a very dense, dark, resin embedded heartwood. The resin embedded wood is valued in many cultures for its distinctive fragrance, and thus is used for incenseand perfumes.