The properties of thin films depend critically on how they are made. For the most part, thin films are assembled in ways very different from the production of bulk materials. Thin films are usually deposited on existing, bulk surfaces using techniques based on atomic or molecular scale physics and chemistry. Physical vapor deposition (PVD) of thin films relies on the removal of atoms from a solid or a liquid by energetic means, and the subsequent deposition of those atoms on a nearby surface. Variations of PVD processes include thermal evaporation, physical sputtering, laser ablation, and arc-based emission. Additional modifications to physical sputter deposition have been made to enhance the chemical and/or structural nature of the deposited films. These modifications include reactive sputter deposition, the unbalanced magnetron; collimated and ionized sputter deposition. Each of these systems and techniques will be described as well as some of the current day applications of the films produced. (C) 2003 American Vacuum Society.