Telephonic transmission is the process of sending and receiving sound or voice signals over a telephone line. It is commonly referred to as a phone call. The most common form of telephonic transmission is the FAX, which is a method of sending documents electronically over a telephone line. FAX is an acronym for facsimile, which is a Latin term meaning 'to make a copy'. Faxing is a popular way to send documents quickly and securely without having to physically mail them.