The StreamMode enumeration defines where the trace events are delivered.

 typedef  enum
 {
   plaFile = 0x0001,
   plaRealTime = 0x0002,
   plaBoth = 0x0003,
   plaBuffering = 0x0004
 } StreamMode;

plaFile:  Writes the trace events to a log file.

plaRealTime:  Delivers the trace events to a real time consumer.

plaBoth:  Writes the trace events to a log file and delivers them to a real-time consumer.

plaBuffering:   Keeps events in a circular buffer in memory only. For more information, see the EVENT_TRACE_BUFFERING_MODE logging mode in [MSDN-LMC].