An event is an entity that describes some occurrence in the system. All events in the system can be represented as XML (though in the protocol they only appear as BinXml, as specified in section 188.8.131.52).
An event is identified by a numeric code (EventID) and a set of attributes (qualifiers, task, opcode, level, version, and keywords). It also contains its publisher name and originating channel, and can also contain event specific data. See [MSDN-EVENTRECORD], [MSDN-EVENT_HEADER], and [MSDN-EVENT_DESCRIPTOR], for a description of the layout of event data structures which contains this information.