Note to explain Tail and Head

Author: SaraTorrey

axon-framework/events/event-processors/streaming.md

@@ -12,11 +12,15 @@ Furthermore, Streaming Processors use separate threads to process the events ret
 Using separate threads decouples the `StreamingEventProcessor` from other operations (e.g., event publication or command handling), allowing for cleaner separation within any application.  
 Using separate threads allows for [parallelization](#parallel-processing) of the event load, either within a single JVM or between several.
 
-When starting a Streaming Processor, it will open an event stream through the configured `StreamableMessageSource`.
+When starting a Streaming Processor, it will open an event stream through the configured `StreamableMessageSource`. The first time a stream has started, it, by default, will begin at the tail (the oldest/the very first token) of the stream.
 It keeps track of the event processing progress while traversing the stream.
 It does so by storing the Tracking Tokens, or _tokens_ for short, accompanying the events.
 This solution works towards tracking the progress since the tokens specify the event's position on the stream.
 
+> **Head or Tail?**
+> 
+> Note that the oldest token is located at the tail of the stream and the latest (newest) token is positioned at the head of the streaming event processor. 
+
 Maintaining the progress through tokens makes a Streaming Processor
 1. able to deal with stopping and starting the processor,
 2. more resilient against unintended shutdowns, and