--- a/doc/book/en/A020-tutorial.en.txt	Mon Dec 22 19:10:38 2008 +0100
+++ b/doc/book/en/A020-tutorial.en.txt	Mon Dec 22 19:54:30 2008 +0100
@@ -5,18 +5,20 @@
 Quick overview of `CubicWeb`
 ============================
 
-`CubicWeb` allows us to develop web applications instances based on
-one or more `cubes`.
+`CubicWeb` is a semantic web application framework that favors reuse and
+object-oriented design.
+
+A `cube` is a component that includes a model defining the data types and a set of
+views to display the data. 
 
-What we call a `cube` is a model defining the data types and views. 
-A `cube` is a reusable component grouped with others cubes in the file
-system.
+An application is a `cube`, but usually an application is built by assembling
+a few smaller cubes.
 
-An `instance` refers to a specific installation of one or more `cubes`
- where are grouped configuration files of the final web application.
+An `instance` is a specific installation of an application and includes
+configuration files.
 
-In this document, we will show you how to create a `cube` and how to use it
-in an `instance` for your web application.
+This tutorial will show how to create a `cube` and how to use it as an
+application to run an `instance`.
 
 .. include:: A02a-create-cube.en.txt
 .. include:: A02b-components.en.txt