UNIX

Foundation of every modern operating system. Basic a principle is that everything is a file and files are streams. Around that is the familiar UNIX structure of the directory tree.

The Internet is built on UNIX. IP addresses and ports at both sides make a socket. Which is a file. Disks are also files, as is the screen. The reason people talk about Internet streaming is due to this fundamental UNIX concepts.

Linux is a type of UNIX.