Resin (Resina) is a viscous liquid that plants such as conifers secrete into bark damages to protect themselves from bacteria, parasites and fungal spores. It is composed mainly of terpenes. Amber is hard fossilized resin.
Resins (Wikipedia) such as frankincense and myrrh have been used since ancient times as incense and in perfumes. In Scandinavia and Russia resin has traditionally been used for fresh and inflamed wounds. Swedish Benedictus Olai mentions use of resin in his medical book in 1578 recommending its use on venous ulcers.
Finnish Medicines Agency Fimea has accepted resin of spruce (Picea abies) as a medicinal compound.