Internet fax, e-fax, or online fax is the use of the internet and internet protocols to send a fax (facsimile), rather than using a standard telephone connection and a fax machine. A distinguishing feature of Internet fax, compared to other Internet communications such as email, is the ability to exchange fax messages with traditional telephone-based fax machines. Fax has no technical advantage over other means of sending information over the Internet, using technologies such as email, , and formats; however, it is extremely simple to use: put the documents to be faxed in a hopper, dial a phone number, and press a button. Fax continues to be used over the telephone network at locations without computer and Internet facilities; and sometimes a fax of a document with a person's handwritten signature is a requirement for legal reasons. Faxes can be sent from electronic devices, often referred to as online faxing which allows faxes to be sent and received without the need for a physical fax machine. Online faxing is still popular as it allows the user to send and receive documents using a secure line without the worry of being hacked, as online faxing services use end-to-end encryption to protect the documents from being hacked. Fax machines have transformed into fax apps or web sites offering fax server services, but the function is still very much a viable part of business transactions. The traditional method for sending faxes over phone lines (PSTN) Fax machine → Phone line → Fax machine A fax machine is an electronic instrument composed of a scanner, a modem, and a printer. It transmits data in the form of pulses via a telephone line to a recipient, usually another fax machine, which then transforms these pulses into images, and prints them on paper. The traditional method requires a phone line, and only one fax can be sent or received at a time. The phone connection must not be a packet-based system in which delays can occur—a VoIP connection will not work well without special precautions (T.38-compliant equipment at both ends).