Where the whole subject starts: machines, wires, and an agreement about how to talk to each other.

A playful backronym sometimes used for "computer": Commonly Oriented Machine Particularly used for Training, Education and Research — not the literal etymology, but a useful way to remember that a computer at its core is a general-purpose machine for processing information, and a network is what happens when many of those machines are wired together to share it.

Before the internet, computers were isolated islands. The story of how that changed:

ARPA founded → ARPANET (research network) → TCP adopted → More hosts join → World Wide Web

• ARPA (Advanced Research Projects Agency) — a U.S. government agency that funded early research into how computers could communicate with each other over long distances.

• ARPANET — the first real packet-switched network ARPA built, originally linking research institutions including MIT, Stanford, UCLA, and the University of Utah, with early links partly carried over satellite connections.

• TCP (Transmission Control Protocol) — the rule-set invented to let independent, dissimilar computer networks reliably exchange data with each other. This is the single biggest unlock: once everyone agreed on TCP, networks could interconnect instead of staying isolated.

• Over years, more institutions, companies, and eventually homes connected — the network of networks became the Internet.

• WWW (World Wide Web) — not the same thing as the internet. The internet is the physical/logical network of connected computers; the Web is a collection of linked documents (pages) that live on top of that network, accessed via HTTP.

At the simplest level, when Computer A wants to talk to Computer B — possibly on the other side of the planet — the message doesn't teleport. It is broken down, addressed, and physically carried across a chain of intermediate devices until it reaches the destination, and a reply makes the same kind of journey back.