--- a/relpipe-data/index.xml	Wed Jul 31 16:01:47 2019 +0200
+++ b/relpipe-data/index.xml	Thu Aug 01 11:59:39 2019 +0200
@@ -164,6 +164,22 @@
 			On the other hand, the already published tools (tagged as v0.x in v_0 branch) should work quite well (should compile, should run, should not segfault often, should not wipe your hard drive or kill your cat),
 			so they might be useful for someone who likes our ideas and who is prepared to update own programs and scripts when the new version is ready.
 		</p>
+		
+		<h2>Big picture</h2>
+		
+		<p>
+			Typical relational pipeline consists of an input filter (left), an output filter (right) and zero, one or more transformations (middle)
+			as outlined on this diagram:<m:podČarou>The diagram was made in the <a href="https://www.mapeditor.org/">Tiled Map Editor</a> 
+			and the tiles (particular pipe graphics parts) come from the game called <a href="http://www.users.waitrose.com/~thunor/pipepanic/">Pipepanic</a>.
+			The tiles used in this diagram are licensed under the <a href="http://artlibre.org/licence/lal/en/">Free Art License</a>.
+			</m:podČarou>
+		</p>
+		
+		<m:img src="img/relational-pipes-big-picture-1.png"/>
+		
+		<p>
+			Data can flow through several transformation or directly from the input filter to the output filter.
+		</p>
 
 		
 	</text>