i must have telephony.
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.
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.
Phone operator 2: Yeah? What did you have to do?
Phone operator 1: I used my telephony to slap them 3 times... I don't think they'll call again, but if they do I'll have to knock them out.