TCOs (Transparent Conducting Oxides) are produced by many techniques; the techniques, TCO properties, and the effects of fabrication variables are reviewed. Few materials are optically transparent and electrically conducting, and these properties are discussed using elementary physics and chemistry, showing that adjusting the fabrication conditions can make improvements. There is specific information in all parts of the visible, near-IR, and near-UV parts of the spectrum, and this information may be used to improve basic properties. The course discusses very large-area applications, such as electro-optical displays and window coatings used to reduce thermal losses, and smaller area applications, such as solar cells and gas sensors. TCOs must be stable and easy to contact. These aspects are commonly neglected and yet are vitally important for their exploitation. Therefore, a full discussion of these aspects is given, based on the instructor's experience with these materials.