The category of software and hardware that allows the Internet to be used as a transmission medium for telephone calls is known as VoIP or Voice over Internet Protocol.  Voice data are currently sent in packets using VoIP instead of POTS circuits.  Many people find VoIP to be very beneficial because net telephony attracts no surcharges beyond the amount users pay for internet access. And at some stage it may even be possible to do reverse phone look up services through VoIP, but that is currently some way off.

VoIP can also be conveniently referred to as "Voice over IP ", because it is a way of using the internet for telephone services  Because VoIP is relatively cheaper than conventional telephone packages, and also high speed internet connection that can serve multiple phone lines, many people prefer it.

The advantages of VoIP are:

The amount you pay for phone calls will be considerably reduced:  Many people no doubt, will jump at the opportunity of making calls; especially long distance ones at reduced rates.  The services offered by service providers varies, some offer free long distance calls, while others charge a token.

Extra features can also be obtained at no charge:  You will get features that are provided at a fee free with VoIP services. These features include Voicemail, Call Forwarding, Call Waiting, Call Transfer, etc and they are all free with VoIP. Other stuff you can get free of charge and for business purpose includes email and web utilities.

There is also tendency to pick your Area Code:  Phone numbers and area codes can be chosen with VoIP services.  Thus, if you want to retain your initial number, you can either transfer it to the new VoIP service or select a new one but based on the area code.