diff --git a/Prog/OOP.md b/Prog/OOP.md
index b5a47a3..3ef19eb 100644
--- a/Prog/OOP.md
+++ b/Prog/OOP.md
@@ -63,4 +63,26 @@ MyFirstClass c = new MyFirstClass(); //new object
 ## Modelization
 
 - First mandatory step
-- 
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+
+- Data modeling
+
+- UML: Unified Modeling Language
+
+  - Class diagram
+  - Class Diagram example:![UML example](https://i.imgur.com/8zGdBkP.png)
+
+  - Code example:
+
+    ```csharp
+    public class MuFirstCar {
+      private string _color;
+      public string GetColor(){
+        return _color;
+      }
+      public void SetColor(string color){
+        _color = color;
+      }
+    }
+    ```
+
+    
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