It began with the telephone. People liked the idea, and gradually a network of wires spread across most continents. Then computers appeared, and they got became popular too, and there were lots of them all over the place. Someone had the bright idea of connecting them together, and this could be easily done if each computer was fairly close to other computers, and thus 'Network' started to become a popular word. Inevitably the idea of connecting to far-distant computers whilst at home or on the move would crop up, and the link between computers and the telephone began.
Computers are digital - they speak in bits of information.
This makes computers think in black and white whereas people are also aware of the shades of grey that exist between. This makes computers much more stupid than people, which is why people like them so much. This is OK for computers, which don't know any different, but is a problem when you want to connect them to the telephone system, which was designed with people in mind. In the meantime the telephone network was beginning to change. Perhaps it had caught a virus from all those modems using it, for it had caught the bug of the bits and was becoming digital also.