This is the science of turning sounds into another type of media (radio, Light, electrical signals, etc), sending them to another location, usually far away, and then back into sound.
Telephony software is software that can be installed on your computer to send sound via modem, or via IP (
VoIP). There is also
telephony software to turn a computer in an advanced fax, and
answering machine.
Telephone: You say "hello", it gets turned into electrical signals, travels
through the wire, then to the phone on the other end, and back into sound, so that the person on the other end hears "hello".
VoIP (Voice over IP): You say "hello" into the mic, the computer turns it into 1s and 0s, sends it into an IP packet, into you cable modem, your ISP will possibly turn that into a fiber optic signal, back into an electrical signal at your VoIP provider. The VoIP provider will then send it to the
phone it needs to go, OR send it to the other VoIP recipient.
