diff -r d1164ba9ac23 -r 1031d4a17a69 doc/book/intro/concepts.rst
--- a/doc/book/intro/concepts.rst	Fri Jul 03 11:37:58 2015 +0200
+++ b/doc/book/intro/concepts.rst	Fri Jul 03 12:07:29 2015 +0200
@@ -15,9 +15,11 @@
 Cubes
 -----
 
-A cube is a software component made of three parts: its data model
-(:mod:`schema`), its logic (:mod:`entities`) and its user interface
-(:mod:`views`).
+A cube is a software component made of three parts:
+
+- its data model (:mod:`schema`),
+- its logic (:mod:`entities`) and
+- its user interface (:mod:`views`).
 
 A cube can use other cubes as building blocks and assemble them to provide a
 whole with richer functionnalities than its parts. The cubes `cubicweb-blog`_ and
@@ -29,7 +31,7 @@
 
 .. note::
 
- The command :command:`cubicweb-ctl list` displays the list of available cubes.
+   The command :command:`cubicweb-ctl list` displays the list of available cubes.
 
 .. _`CubicWeb.org Forge`: http://www.cubicweb.org/project/
 .. _`cubicweb-blog`: http://www.cubicweb.org/project/cubicweb-blog
@@ -41,21 +43,16 @@
 Instances
 ---------
 
-An instance is a runnable application installed on a computer and based on a
-cube.
+An instance is a runnable application installed on a computer and
+based on one or more cubes.
 
-The instance directory contains the configuration files. Several instances can be
-created and based on the same cube. For exemple, several software forges can be
-set up on one computer system based on the `cubicweb-forge`_ cube.
+The instance directory contains the configuration files. Several
+instances can be created and based on the same cube. For example,
+several software forges can be set up on one computer system based on
+the `cubicweb-forge`_ cube.
 
 .. _`cubicweb-forge`: http://www.cubicweb.org/project/cubicweb-forge
 
-Instances can be of three different types: all-in-one, web engine or data
-repository. For applications that support high traffic, several web (front-end)
-and data (back-end) instances can be set-up to share the load.
-
-.. image:: ../../images/archi_globale_en.png
-
 The command :command:`cubicweb-ctl list` also displays the list of instances
 installed on your system.
 
@@ -102,12 +99,6 @@
 updated and deleted. As the default user interface is not very fancy,
 it is usually necessary to develop your own.
 
-It is common to run the web engine and the repository in the same
-process (see instances of type all-in-one above), but this is not a
-requirement. A repository can be set up to be accessed remotely using
-Pyro (`Python Remote Objects`_) and act as a standalone server, which
-can be directly accessed or also through a standalone web engine.
-
 .. _`CRUD`: http://en.wikipedia.org/wiki/Create,_read,_update_and_delete
 
 .. _SchemaIntro: