A media server refers either to a dedicated computer appliance or to a specialized application software, ranging from an enterprise class machine providing video on demand, to, more commonly, a small personal computer or NAS (Network Attached Storage) for the home, dedicated for storing various digital media (meaning digital videos/movies, audio/music, and picture files).
By definition a media server is a device that simply stores and shares media. This definition is vague, and can allow several different devices to be called Media Servers. It may be a simple Network-attached storage, a Home theater PC (HTPC) running Windows XP Media Center Edition, MediaPortal or MythTV, or a commercial web server that hosts media for a large web site. In a home setting, a media server acts as an aggregator of information: video, audio, photos, books, etc. These different types of media (whether they originated on DVD, CD, digital camera, or in physical form) are stored on the media server's hard drive. Access to these is then available from a central location. It may also be used to run special applications that allow the user(s) to access the media from a remote location via the internet.
A media server can also be an appliance which combines the necessary hardware and software combinations to offer Audio Visual content over the Wi-Fi Network. In a business setting such as a hotel, residential complex, hospital or airport, a Zapelin Media Server (ZMS) [1] can be used to transform DVB-T, DVB-S, IPTV content into a streaming format so that this content can be "injected" into the Wi-Fi Network. An appliance such as the ZMS is also capable of taking content of IPTV source to be transformed to a DVB-T format that can be "injected" into the coaxial network. This means that it is possible to provide IPTV content to all the TV's without the need of set-top box or Internet connections in each room.