Very simply, streaming is broadcasting live video over the Internet. A video stream is different to a video file.
A video file must finish recording before you can upload it, but a video stream continues live until you stop it.
Everyone from the largest broadcaster and media organisation, to police forces, houses of worship and gamers are streaming live to mobile devices, iPads, networked screens, computers, consoles… It’s the fastest growing part of the media industry, worth an estimated US$14 billion worldwide.
You first need to compress the video into a size that you can reliably upload to the Internet, and to do that you either use hardware or software.
If you use hardware encoders you don’t need a computer, so the equipment is smaller and can even be mounted on a camera.
If you use software you still need to get the video signal into a computer, and there are boxes that do this too.