Student or Learner
In the sentences below, which is written about the history of how to communicate information, what does "yesterday, or the day before" mean?
...The fourth great change, electronic communication, took place yesterday, or the day before, depending on how you measure it. The Internet dates from 1974, at least as a term. It developed from ARPANET, ...."
I guess it is a sort of figurative expression. If so, does it simply mean "a little while ago"?