diff --git a/book/chapter-01-run-and-talk.md b/book/chapter-01-run-and-talk.md
index f17c9813..c944688c 100644
--- a/book/chapter-01-run-and-talk.md
+++ b/book/chapter-01-run-and-talk.md
@@ -14,9 +14,14 @@ gbapp and gblib are responsible for GeneralBots services in a Back-end developme
 Angular, Riot, React and HTML are responsible for the dynamic functioning of GeneralBots services.
 
 3- The .gtheme extension is responsible for the GeneralBots designer using css and PS technologies.
+A theme is composed of some CSS files and images. 
 
 4- .gbDialog and .gbkb are extensions responsible for GeneralBots communication with the end user. Dialogues are bot services to users.
 
+5- the .gbot extension refers to the generalBots service product.
+
+6- the .gbai is architecture
+
 ### The Bot Factory
 
 ![General Bots Block Architecture](https://raw.githubusercontent.com/pragmatismo-io/BotServer/master/docs/images/general-bots-block-architecture.png)