An introduction to computer audio
Audio files are stored on a hard disk. You have two options to access them:
A PC has the audio files stored on a local HD and/or on a server somewhere in your home network.
A streaming audio player in general doesn't have a HD. It gets it music from a server. You connect to a server by providing its IP-address, browse its contents and choose a song.
Pretty much the same way as you surf the internet using your browser.
To play your own music using a streaming audio player:
After configuring everything correctly, the media player can access your collection over the home network.
A bit more complex compared with a PC.
If you want to give it a try and you have a PC running Vista or XP and a media player you can enable the media sharing and connect a media player.
If you have 2 PCs, enable media sharing and they can both play the content on the other (Vista, XP can only act as a server)
There are more differences.
Power consumption
Well designed NAS and a media players use less power than a PC.
A lightweight NAS might consume 15 Watt, a Squeezebox probably 5 Watt, a laptop probably 60 Watt
What is sold as “music server” is in general a dedicated computer.
Most of them are not servers properly as you can control them directly.
But a lot of them can be used as a server as well.
They have the look and feel of traditional audio equipment. In fact some companies stress that it is NOT a computer. They probably think they fence people of by calling it what is, a computer. More can be found here