What it actually means
Streaming means the file plays as it arrives. Your TV or phone holds a few seconds of video in a buffer, decodes it on the fly, and discards it once you have watched it. Nothing permanent is saved to the device, which is why a flaky connection turns straight into a spinning wheel rather than a slightly slower start.
The quality you get depends on how much bandwidth the line can spare in that moment. Standard definition wants about 3 Mbps. HD wants roughly 5 Mbps. 4K needs around 25 Mbps for a single stream. A household rarely runs one stream in isolation. The living room might be on Prime Video while a teenager is on YouTube upstairs and a smart speaker is pulling music from Spotify in the kitchen, and that 25 Mbps figure quietly becomes 50 or 60. The honest measure of a good broadband line for streaming is whether it holds steady across a busy evening, not whether the headline number on the brochure says 'up to' something impressive.
At home
What this looks like in the house
Streaming shows up as a felt thing in a house. It is the Sunday evening when the whole family is settled in front of a film and the picture drops to a blurry mess just as something important happens on screen. It is the kid in the back bedroom whose YouTube keeps reloading while the rest of the house is fine. It is the moment everyone looks at the router and someone gets blamed. A line that streams without drama on a Sunday at 8pm is doing its job, whether the speed test claims 200 Mbps or 900.
In business
What this looks like at work
For a hospitality business, streaming is a guest experience problem. The hotel guest who cannot get Netflix to load in their room is one star already, before they have decided whether to leave a review. The holiday park caravan owner whose grandchildren cannot watch iPlayer turns into a refund conversation by the weekend. Offices feel it too when a team tries to pull a webinar or training video and the picture stutters for half the room.