VoIP is similar to that used by internet-based providers because VoIP telephone handsets that look and work  much like traditional telephones, except that instead of being wired to a telephone line, they're either directly connected to your computer (by something like a USB cable) or indirectly connected to it by a wireless (Wi-Fi) router.Apart from the initial logging on process, there is no intermediate computer managing the communication between the sender and receiver, which makes Skype relatively secure compared to other forms of telephone communication [2].You'll find a slightly different kind of VoIP on cellphones (mobile phones).In other words, they're using packet switching over the cellphone network.