Conversation

For background and history on the concept of sending data, first check out this stackoverflow question/answer set, which includes a great diagram on what it looks like to 'call' another computer https://electronics.stackexchange.com/questions/68790/how-does-a-signal-travel-down-a-telephone-wire

And then take a look at how they ran telephone wires, set up microwave towers to handle longer distance, and eventually an entire world wide network http://www.telcomhistory.org/vm/scienceLongDistance.shtml

Then try this exploration of how it shifted to telephone-over-internet (+beyond?)
https://medium.com/@aantonop/why-dumb-networks-are-better-f0b94c271b76