Thin films have recently acquired a fundamental role, as they are strategically important in the advancement of cutting-edge technologies. Their application extends to a wide variety of fields—for instance, in energy, for coatings in solar cells and batteries; in electronics, for integrated circuits and displays; in optics, for anti-reflective coatings and filters; and in biomedicine, for antibacterial coatings and biosensors. These coatings consist of extremely thin layers of material, with thicknesses ranging from just a few nanometers to several micrometers, deposited on different types of substrates. These substrates can vary from rigid inorganic materials such as glass, silicon, or ceramics (e.g., Al2O3 and ZrO2) to metallic ones, including copper, aluminum, and their alloys. The purpose of this process is not only to protect the surface but also to modify or enhance essential properties, such as electrical conductivity, optical behavior, or mechanical resistance, depending on the needs of each application.