Back in the day… before the Internet was a thing… there were Computerized Bulletin Board Systems (BBSes).  These would use modems (modulators-demodulators) to encode signals for transmission over the telephone network so that people could communicate with people wherever they could find someone else with a phone line and a modem.  The speeds were very slow when contrasted with modern day communications systems, however they were good enough to allow for store-and-forward message systems such as echomail and instant chat, as well as allowing for the sharing of small mp3 music files.  The basics needed for truly global communications was in place in the BBS era.  The Internet soon eclipsed the functionality of BBSes, however BBSes didn’t all stop from being online, in fact in the past half-decade BBSes have had a large resurgence in sysops running boards for nostalgia and to serve peoples’ needs using technology that isn’t massively tracked or having targeted advertising that harvests users personal data for marketing purposes.  We like the good old days of systems run for the sake of serving others rather than advertising things to us on a continual basis