strēam

Old English strēam meant a flow of water — a river, a brook, a current. It descended from Proto-Germanic *straumaz, which also produced German Strom (river, current, electricity) and Dutch stroom. The Indo-European root *sreu- meant to flow, and it branched into Greek rhein (to flow), giving English rhythm, rheumatism, and diarrhea. Water words are old. Humans named moving water before they named almost anything else.

The metaphorical use — a stream of people, a stream of consciousness — appeared in English by the 1600s. William James coined 'stream of consciousness' in his 1890 Principles of Psychology to describe the unbroken flow of thought. James chose stream deliberately. Thought, he argued, does not arrive in buckets. It flows. The metaphor worked because everyone had watched a river.

In 1995, the companies Progressive Networks (later RealNetworks) and Microsoft began delivering audio over the internet in real time, calling it streaming. The word was perfect. Traditional downloads were like filling a bucket: you waited for the whole file, then used it. Streaming was like drinking from a river: the data flowed continuously, and you consumed it as it arrived. The technical term for this is progressive delivery, but nobody says progressive delivery. They say streaming.

Netflix launched its streaming service in 2007. Spotify followed in 2008. By 2020, streaming had largely replaced physical media, broadcast television, and most forms of scheduled programming. The word that began as a name for running water now describes how most humans on earth experience music, film, and television. The river metaphor held because the physics are genuinely analogous: data flows through fiber-optic cables the way water flows through a channel, and both stop when the source dries up.