Streaming media refers to publishing multimedia (audio, video, ... ) as a "stream". In contrast to a normal file transfer, "streaming" means you can start using the file before it's completely downloaded; your media player starts reading (and displaying) the file while it's still being downloaded. This is very convenient for large files such as movies, and for files that have no known "end-of file" yet, such as a live radio broadcast ("live stream"). Media streams can also be initiated by the server ('push' technology), with the clients acting as receivers, similar to a traditional TV or radio broadcast (whereas in a normal file transfer, the client requests the download).
You can set up a streaming media server as added value to your small business Linux server
A media server on a local network allows you to centrally manage your movie or music collection while having it available on any host of the network. More advanced configurations will let you broadcast ("multicast", see further) audio, video, announcements, pictures, ... to all or a selection of host to your network, or server content "on demand".
This works on Debian 4.0, and should work equally well on Ubuntu.
You'll need a server with adequate disk space for your media files. On machines younger than 5 years, CPU and RAM won't be an issue for home networks. You need a network with acceptable speed. A 10/100 mbps LAN will do fine. For larger setups (corporate networks, internet service, ...), you
Your clients will need a web browser and a media player. Not all players can handle all types of streams, especially windows clients or other proprietary software (iTunes ?). Linux media players can usually handle any type of stream you throw at them, but may have trouble with some proprietary file formats / media codecs, although there are workarounds for most cases.
I helps if you have some network infrastructure such as dns and dhcp in place, this helps to create a more agreeable user experience. refer to small business Linux server.
If you want a streaming server up and running in under 5 minutes, here's the plan : Audio streaming with Gnu mp3 daemon (gnump3d).
gnump3d apparently only works for audio (ogg, mp3 and m3u formats). No video.
Other streaming audio servers
the Videolan project provides software for all sorts of streaming (video, audio, graphics) in all sorts of setups (point to point, multicast, on demand, ...), from a wide range of sources (files, other streams, devices such as web cams, terrestrial and satellite TV, ... ) with support for transcoding (conversion of stream types and file formats), saving a stream to a file, etc.
Despite this wide range of functionality, Videolan (vlc) is relatively easy to set up, due the the modular nature of the software : you only install what you need for a particular feature, and you can expand it later as you become more ambitious.
Some examples of streaming media configurations