The Difference Between Downloading and Streaming

Summary

What’s the difference between “streaming” and “downloading” video, audio, or some other kind of linear media? Many platforms make a firm distinction between streaming and downloading, implying that they’re very different. But they’re not. They’re basically the same thing Despite what various platforms would have you believe, there’s no significant technical difference between streaming and downloading. Suppose you’re choosing whether to download or stream a video. In both cases: The server gets frames of video from a source (file, livestream, etc.) The server sends those frames to your device Your device stores them while it does something with them Want to keep a copy of this animation? You don’t have to trick your computer into retaining it as it streams because I’ve open-sourced it, and the code used to produce it. So what’s the difference? The fundamental difference between streaming and downloading is what your device does with those frames of video: Does it show them to you once and then throw them away? Or does it re-assemble them all back into a video file and save it into storage? When you’re streaming on YouTube, the video player running on your computer retains a buffer of frames ahead and behind of your current position, so you can skip around easily: the darker grey part of the timeline shows which parts of the video are stored on – that is, downloaded to – your computer. Buffering is when your streaming player gets some number of frames “ahead” of where you’re watching, to give you some protection against connection issues. If your WiFi wobbles for a moment, the buffer protects you from the video stopping completely for a few seconds. But for buffering to work, your computer has to retain bits of the video. So in a very real sense, all streaming is downloading! The buffer is the part of the stream that’s downloaded onto your computer right now. The question is: what happens to it next? All streaming is downloading So that’s the bottom line: if your com...