Sandalwood is a class of woods from trees in the genus Santalum. The woods are heavy, yellow, and fine-grained, and, unlike many other aromatic woods, they retain their fragrance for decades. Sandalwood oil is extracted from the woods for use. Sandalwood is often cited as one of the most expensive woods in the world.
Agarwood or oodh (or just agar) is a dark resinous heartwood that forms in aquilaria and gyrinops[1] trees (large evergreens native to southeast asia) when they become infected with a type of mold. Prior to infection, the heartwood is relatively light and pale coloured; however, as the infection progresses, the tree produces a dark aromatic resin in response to the attack, which results in a very dense, dark, resin embedded heartwood. The resin embedded wood is commonly called gaharu, jinko, aloeswood, agarwood, or oud (not to be confused with 'bakhoor') and is valued in many cultures for its distinctive fragrance, and thus is used for incense and perfumes.
