The modern Telephone system evolved from the Telegraph as a concept for a "Speaking Telegraph" that would enable not just morse code through a series of beeps and dashes, but true speech through ordinary verbal communication.
The idea was pioneered by a number of different inventors but the works of Alexander Graham Bell  are most commonly cited for contributing to the modern telephone system.
Telephony is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the invention and development of the telephone. Telephony is commonly referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires. The term is also used frequently to refer to computer hardware, software, and computer network systems, that perform functions traditionally performed by analog telephone equipment. If a telephony system transmits voice signals over the Internet Protocol then it is called a VoIP system.
Digital Telephony is the use of digital electronics in the operation and provisioning of telephony systems and services. Since the 1960s a digital core network has replaced the traditional analog transmission and signaling systems, and much of the access network has also been digitized. Digital telephony has dramatically improved the capacity and quality of the network, while simultaneously lowering the total cost of ownership and maintenance of the network.
- Twilio - Cloud-based Telecommunication (virtual switchboard) solution: http://www.twilio.com/how-twilio-works
- Telephone Number Identification System: http://tnid.us/
- YellowPages API: http://www.yellowapi.com/
- WhitePages API: http://developer.whitepages.com/
- The evolution of telephones: http://www.techrepublic.com/photos/the-evolution-of-telephones/6343054
- Internet Tip # 6 - Discover Cellular Phone Number Provider or find out if your friends # is free for you to call/receive calls from: http://www.seabreezecomputers.com/tips/phone.htm
- wikipedia: Telegraph
- wikipedia: Telephone
- wikipedia: Telephone network
- wikipedia: Plain old telephone service (POTS)
- wikipedia: Landline
- wikipedia: Alexander Graham Bell
- wikipedia: Invention of the telephone
- wikipedia: History of the telephone
- wikipedia: Telephony
- wikipedia: List of telephony terminology
- wikipedia: Automatic number identification
- wikipedia: Dialed Number Identification Service
- wikipedia: Caller ID
- wikipedia: IVR
- wikipedia: PBX
- wikipedia: Digital loop carriers (DLC)
- wikipedia: Local loop
- wikipedia: Digital signal
- Giant IoT Public Telephone Screens Open to Advertising in NY: http://www.mediapost.com/publications/article/256098/giant-iot-phone-screens-open-to-advertising-in-ny.html