Linked from
The 13 pages that link to Steam distillation, each with the reason it gives.
FrankincenseRelated: It is commonly used to produce frankincense essential oil from resin.
SteamRelated: Steam carries volatile compounds from materials such as plants.
CinnamaldehydeRelated: Steam distillation can extract cinnamon bark oil containing cinnamaldehyde.
VaporizationBroader topic: It applies vaporization to isolate heat-sensitive volatile substances.
Fragrance compoundRelated: It is a longstanding way to obtain aromatic compounds from plants.