What is VoIP?

VoIP stands for Voice over Internet Protocol, and it is the reason a call to another country now costs close to nothing. Here is what actually happens to your voice on the way.

The one-sentence version

VoIP stands for Voice over Internet Protocol. It means your voice is carried as ordinary internet data, the same kind of data as a video stream or a downloaded file, instead of travelling over the dedicated telephone network.

What actually happens to your voice

The microphone captures your voice as sound waves. Software converts that sound into digital data, compresses it using something called a codec to keep the file size small, and slices the result into a stream of small packets. Those packets travel across the internet exactly like any other data, and get reassembled into sound on the other end, ideally so quickly you never notice the round trip.

Why it caught on

Because VoIP rides on internet infrastructure that already exists for everything else, it needed no dedicated telephone wiring to reach you. That single fact is why VoIP calls are so much cheaper than traditional calls, especially internationally, where a landline call would have needed physical circuits crossing entire countries and oceans.

It is also why an office can run its entire phone system through a PBX connected to the internet instead of a room full of physical phone lines.