One of the neat things that you can do with the Internet is use it to make phone calls. This is made possible by a set of technologies that adapt the functions of traditional telephones to modern computers and mobile devices. Collectively, these technologies are known as “voice over Internet protocol” (or VoIP).
What is VoIP?
VoIP is a term used to describe the process of sending voice signals over the Internet, as well as the set of technologies that make it happen. Basically, for VoIP to work on your computer, you need an Internet connection (obviously), a microphone (so you can send sound into your computer), a sound card (so your computer can process sounds coming into or out of it), and speakers (so you can hear the other person). Many modern computers have most or all of these things on-board when you buy them.
VoIP works by taking the analog audio signal that’s produced when you speak into the microphone and processing it through your computer’s sound card. This turns your voice into a digital signal that is easier for your computer to work with. Your digital voice is then split into chunks (so it’s easier to move) and then sent over the Internet to the other person on the call. When it reaches the other person’s computer, their computer’s sound card re-assembles your digital voice into an analog one that can be understood by human ears, and plays it out through the other person’s speakers.
Services that offer free Internet calls (via VoIP)
There are several popular services on the Internet that make VoIP easy to use, and most of them are in large part free to use. However, many only allow you to make free Internet phone calls to other people on the Internet, and/or who use the same service. While it is possible to use VoIP to make a call from the Internet to a traditional phone, or vice-versa, many services charge money for it.
Here are three of the best-known free Internet calling services:
Skype allows users to make free phone and video calls to other people who use the service. It also has support for text messaging, file sharing, group calls, and recorded messaging (both voice and video). In addition, users can send phone calls to regular phones with Skype and vice-versa, but this costs money. Skype is one of the most popular VoIP services because it is easy to set up and use.
If you’d like to learn more about how to use Skype, visit our Skype Course.
ooVoo is another VoIP service that offers many of the same functions as Skype. Two of its unique features (besides its rather unique name) are that users can watch videos on YouTube together while having a voice chat, and can start and stop recording a phone or video call at any time. Phone and video calls between ooVoo users are free, but ones between ooVoo and regular phones are not.
UPDATE: As of November 25th, 2017, ooVoo has shut down.
Viber is a VoIP service that is designed like a social network. It offers many of the same features as Skype and ooVoo, but it also has functions like special “mood stickers” that you can buy or earn to show others how you’re feeling, as well as public chat rooms where you can discuss various topics. Like many VoIP services, phone and video calls between Viber users are free, but ones between Viber and regular phones cost money, and are limited to certain mobile devices.