Update Configuration.md

Configuration.md

@@ -112,9 +112,21 @@ In the DES processor operation declarations the authentication entry can be refe
 	<Recursive>true</Recursive>
 </Consumer>
 ```
+  
+## Processor configuration file
+  
+  
+The DES executes concurrently a given set of Processor definition files that are defined in XML format.
+A processor configuraiton file ( *.processor_config.xml ) is the basic executable entity for the DES. 
  
- 
-    
+There can be 1 - n processor configuration files running on a given DES instance. 
+Each processor configuration file can have 1 - n AOIs (Areas Of Interest).
+Each AOI can have 1 - n functional entities (*Distribution, Download, Task, TaskGroup, DataCleaner*) 
+The same xml format is used also by EGPF (Eurac Generic Processor Framework)
+
+See Processor_configuration for the configuration options.
+
+  
 ## Start a DES instance ##