Sputtering is a physical process where small particles are ejected from a solid surface when it is bombarded by energetic particles, such as ions. This technique is commonly used in materials science and engineering to deposit thin films of materials onto surfaces, which can enhance their properties or create new functionalities. In the context of vacuum deposition, sputtering is often employed to coat objects with metals or other materials. The process involves creating a plasma, which generates ions that collide with a target material, causing atoms to be ejected and deposited onto a substrate, forming a thin layer.