Etching is a process of marking on metal by using acid or other corrosive substances to cut into the surface. It is a popular technique used in many industries, such as jewelry making, printing, and engraving. Etching is also used to create decorative designs on metal surfaces. The process involves creating a design on the metal surface and then using an acid or other corrosive substance to cut into the metal. The result is a permanent mark that can be used for decoration or identification.