Thin-film technology is a field dedicated to the science, engineering, and application of materials in the form of layers ranging from atomic monolayers to several micrometers in thickness. This domain investigates the unique physical, chemical, electrical, optical, and mechanical properties exhibited by materials when confined to such reduced dimensions, often differing significantly from bulk material properties due to surface and interface effects, quantum size effects, and controlled microstructure. Its significance lies in enabling the precise fabrication of advanced functional devices and protective coatings critical to numerous applications across diverse technological sectors, including electronics, photonics, energy conversion, and surface science.