eli5: What really happens under the hood when we get to video chat in real time to someone that is on other side of world?

Question

I’m wondering how is this information actually transferred, how it can be that fast that we can see without any latency at all.

Thanks in advance,

In: 20

Answer 1

>how it can be that fast that we can see without any latency at all

Actually there is some latency.

These days we have variable bit rates, so instead of cutting out completely when latency gets too high your video will decrease in quality temporarily.

Eventually we may be able to send data around the world, reliably, at the speed of light, and perhaps some day faster with quantum computing, but it’s going to be a while still.

>I’m wondering how is this information actually transferred

As ones and zeros, represented by pulses of electricity or light, across wires, fiber optic cables, and radio waves.

Over many decades, we have improved both the quality and capacity of those physical mediums, the manner in which that data is prepared for transmission (encoding), and the process of transmission itself (protocol).

Between you and the person you are calling, your video data is encoded, possibly encrypted, and compressed. That could be done on your phones themselves, but it would use a lot of CPU, battery, and get pretty hot. More likely this workload is shared between your phones and servers in the network of whichever application you are using.