Great post by Daryl Koopersmith over at Medium about the history of the internet and domain names.
Before the internet, before domain names, and before I was born, there was the ARPANET — the little network that could. What started as a network that bridged four research centers in the western United States became the foundations of the internet we know today.
The ARPANET connected computers called hosts together using giant, wired routers called Interface Message Processors (IMPs). These routers served as the nodes of the network, and allowed the research centers to communicate with one another.
— Read on medium.engineering/use-a-dev-domain-not-anymore-95219778e6fd