Unity stream video tutorial?

Hi
Recently I’m starting to learn how to stream video in Unity (You have video file in server, and you can download and play at the same time), but I dont know where to start, there is no tutorial online, anyone knows where to start. I know there are plenty of plug-ins, but I want to learn how it works.
Thanks:)

I have used following plugins for streaming in iOS :

To Stream audio: Audio Stream in iOS | Audio | Unity Asset Store

To Stream Video : Video Streaming in iOS | Integration | Unity Asset Store