diff --git a/slides/cloneRepo.md b/slides/cloneRepo.md
index 7f386066a8822f41b05e5a21e71f7656c89d375a..e4d78710d341605009d8433df5555acf56a1c4cb 100644
--- a/slides/cloneRepo.md
+++ b/slides/cloneRepo.md
@@ -12,25 +12,56 @@ If you did not configure your SSH key, clone using HTTPS:
 ```bash
 $ git clone https://github.com/userName/myRepo.git myRepo
 ```
-<br>
 
+<br>
 <div class="fragment">
 You will be prompted to enter your credentials.
 
 
+## What is a `fork`?
+
+<div class="fragment">
+<img src="img/fork.jpg" class="as-is" />
+[//]: <> (http://www.cndajin.com/data/wls/246/22302193.jpg)
+
+
+## Not really ...
+<img src="img/fork-crossed.png" class="as-is" />
+
+
+## What is a `fork`?
+In general, when contributing to a repository, you only have **read** access.
+
+<div class="fragment">
+In other words, you can only **pull** (unless it is your own repository or access has been granted).
+
+<div class="fragment">
+<br>
+In general, you **cannot write** changes. In other words, you do not have **push** access.
+
+<div class="fragment">
+You have to work on your **own copy**.
+
+<div class="fragment">
+<br>
+In other words, you have to work on your own <font color="red">fork</font>.
+
+
 ## Time to practice!
 
 (Live Demo)
 
 <br>
 
-Clone the practice repository: <br><br>
+Fork the practice repository: <br><br>
 https://git-r3lab.uni.lu/R3.training/git.practice
 
+Then, clone your fork to your home directory!
+
 <div class="fragment">
 <br>
 ```bash
-$ git clone ssh://git@git-r3lab-server.uni.lu:8022/R3.training/
+$ git clone ssh://git@git-r3lab-server.uni.lu:8022/yourUserName/
   git.practice.git practice
 ```
 
diff --git a/slides/list.json b/slides/list.json
index 3055407152890f7c42523c323fb060a1b85ceaff..cab3401b90d90008aef509b0747a34320869033e 100644
--- a/slides/list.json
+++ b/slides/list.json
@@ -30,13 +30,13 @@
         }
     },
     {
-        "filename": "github_gitlab.md",
+        "filename": "installation.md",
         "attr": {
           "data-background": "img/whiteBG.jpg"
         }
     },
     {
-        "filename": "installation.md",
+        "filename": "github_gitlab.md",
         "attr": {
           "data-background": "img/whiteBG.jpg"
         }