Impedance matching is a technique used in electrical engineering to ensure that the output impedance of a source matches the impedance of the load it is connected to. This maximizes the transfer of power between the source and the load, minimizing reflected power and signal loss. Impedance matching is important in various applications such as antennas, audio systems, and RF circuits to achieve optimal performance and efficiency. Techniques used for impedance matching include transformers, baluns, and matching networks.