In polymer chemistry and materials science, a resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses mainly on naturally occurring resins.

Boswellia sacra, also known as Boswellia carteri and others, and commonly called the frankincense tree or the olibanum tree, is a tree in the genus Boswellia, in the Burseraceae family, from which frankincense, a resinous dried sap, is harvested. The olibanum tree is plant native to the countries of Oman and Yemen, in the south of the Arabian Peninsula, and to Somalia, in the Horn of Africa.