The term Dubbing technically refers to the process of transferring or duplicating audio material from one medium to another, such as copying the content of a master tape to a backup copy. It was a very common term in the era of dual-cassette tape recorders (double deck) to describe tape copying. The definition also covers the practice of adding new sounds to an existing recording, although this specific process is nowadays almost universally called "Overdub" or layering by audio professionals. It is worth noting the distinction with the popular use of the word "Dublagem" in Brazil, which focuses specifically on replacing dialogue in films and series, whereas in the studio the term is more linked to technical transfer and duplication.