To understand how and why VoIP is necessary, you must first understand how the Internet file transfer. In simple terms what the VoIP service does is to convert an analogue audio signal into a digital audio signal that can be transferred over the internet. In order for a file to be transferred over the internet from one computer to another, the signal has to be cut down into small pieces, called 'packets'. This can only be done if the information being cut up is in binary format, i.e. in the form of a stream of 1s and 0, such as 11000010. very basically, such a stream of binary digits can be cut into small packets such as 1100 and 0010 , sent over the internet, then put back into order when received to read 11000010. As I said, this is a simple example, purely to give a rough idea of how a...