thearchivist.funARPANET connects four early sites
ARPANET began operating as a four-node research network in 1969.
Context and provenance
DARPA describes ARPANET's 1969 activation as a four-node beginning in a much longer development. The network connected geographically separated computers so that digital resources could be shared across research sites. It was a working experiment, not the fully formed internet familiar today. Over the following two decades, the broader networking environment expanded and changed; ARPANET was eventually deactivated as a much larger network of networks emerged. This distinction helps separate several histories that are often compressed into one origin story: an individual research network, the protocols that allow different networks to communicate, and the later Web used to publish linked documents.
Why it matters
Editorial perspective: A network becomes useful through relationships between participants. Its history resists the idea of a single launch that instantly produces a finished system; growth depends on interoperability, institutions, and repeated practical adaptation.