diff --git a/agora pkg chapter.md b/agora pkg chapter.md
index b3f23296b..bb703b0ff 100644
--- a/agora pkg chapter.md	
+++ b/agora pkg chapter.md	
@@ -68,7 +68,7 @@ The Agora can be defined in a nutshell as a subset of the [[internet]][^web] use
 ## Terminology
 
 - [[Agora]]: a [[protocol]], a [[platform]], a [[commons]].
--
+- [[Graph]]: the heart of the Agora. A distributed [[knowledge graph]] in particular, both explicitly and implicitly containing a variety of social graphs.
 
 # Principles