Rosin-based flux is a type of chemical used in soldering to help join metal parts together. It is made from natural resin, often derived from pine trees, and helps to clean the surfaces of the metals being soldered. This cleaning action allows for better adhesion of the solder, ensuring a strong and reliable connection. In addition to its cleaning properties, rosin-based flux also protects the metal from oxidation during the heating process. This is important because oxidation can interfere with the soldering process. Commonly used in electronics, rosin-based flux is favored for its effectiveness and relatively low toxicity compared to other flux types.