I've written already about natural ambergris (also called Ambra) and mentioned there that most perfumery uses synthetic substitutes.
Here I'm setting out some of those substitutes (mainly synthetic, but including some naturals) and trying to sort out some of the confusion resulting from the fact that there are so many different products with very similar names.
The ambreine produced from labdanum, also sometimes confusingly called Cistus oil, is a steam distilled product from Cistus ladaniferus. I have been told by a leading producer of both labdanum absolute and cistus essential oil that the difference between the two products is as follows: Cistus oils are produced by steam distillation of the entire top-growth (twigs, leaves, stems and flowers) of the Cistus ladaniferus plant - a cistus absolute is sometimes also produced from the top-growth. Labdanum products, by contrast, are produced from a gum-resin found on the roots of the plant, which are first washed and then mechanically agitated to separate the gum from the rest of the roots, an essential oil, absolute and resinoid of labdanum are all produced from this gum-resin.
Ambrarome (from Synarome) and Ambrain (from IFF) are similarly extracted by proprietary processes from the labdanum resin (referred to as gum-labdanum sometimes though I think incorrectly - see details in this post for definitions). These are highly animalic in smell and designed as plant-based alternatives to the traditional animal components of perfumery.
Ambrox is a term usually used to mean Ambrox DL or one of it's synonyms: quite different from the labdanum based materials because it's a brand name for a single synthetic molecule (though a mixture of isomers) which replicates one of the components of natural ambergris. The term ambrox is sometimes used to mean any of a range of similar products, in particular Ambroxan / Ambrofix / Orcanox that are brand names for chiral isomers [specifically (-)-Ambroxide], which though similar, are not quite the same. In my work I mainly use Ambrofix, which is made by Givaudan from a natural starting material, though I do use some of the others too.
Just to confuse matters further there is also Ambrein which is the waxy substance that is the majority component of natural ambergris, the breakdown products of which give the precious scented molecules of ambroxide and others that have been replicated by the various brand-named products above. When pure, ambrein is odourless. Bo Jensen provides a good description of what's going on (scroll down to the text just below the whale pictures). I also use several of the other substitutes mentioned by Bo Jensen in his article for particular purposes.
Further confusion often arises between Ambergris (Ambra) products and Amber - a term that in perfumery is sometimes used to refer to a product made from the fossil amber by destructive distillation of the waste and low-grade amber left over form the jewellery trade. This is described by Arctander as having a "smoky, tarlike, resinous" odour "with a distinct resemblance to the smell of tanned leather". He mentions that there is also a rectified version of this oil, which has been steam distilled as well, but he says that this is "very little used in perfumery".
More often however amber refers to a blend of ingredients intended to give an warm scent reminiscent of both ambergris and the appearance of fossil amber (which in its raw state has virtually no odour). Such blends normally include labdanum, vanilla, benzoin and other ingredients; are are often used as fixatives. Some of the products named in the first paragraph fall into this category, but many perfumery houses and others will have their own blend.