A universal plug and play (UPnP) device makes itself known through a set
of processes--discovery, description, control, eventing, and
presentation. Following discovery of a UPnP device, an entity can learn
more about the device and its capabilities by retrieving the device's
description. The description includes vendor-specific manufacturer
information like the model name and number, serial number, manufacturer
name, URLs to vendor-specific Web sites, etc. The description also
includes a list of any embedded devices or services, as well as URLs for
control, eventing, and presentation. The description is written by a
vendor, and is usually based on a device template produced by a UPnP
forum working committee. The template is derived from a template language
that is used to define elements to describe the device and any services
supported by the device. The template language is written using an
XML-based syntax that organizes and structures the elements.
