Tree resin is a sticky substance produced by certain trees, primarily conifers like pine and spruce. It serves as a protective mechanism, sealing wounds and deterring pests and pathogens. The resin can harden when exposed to air, forming a solid material known as amber over time. Resin has been used by humans for various purposes, including making varnishes, incense, and traditional medicines. It is also a key ingredient in products like turpentine, which is derived from pine resin and used as a solvent. The unique properties of tree resin make it valuable in both natural ecosystems and human applications.