Added new CLI sections to branching basics.

04-branching-basics/README.md

@@ -19,4 +19,39 @@ Working on the project's content in a specific branch is no different from worki
 ![gitlab-branch-edit.mp4](./media/gitlab-branch-edit.mp4)
 
 
+## Using the CLI to manage branches
+
+In the GitLab UI, working in a branch is performed by selecting a branch from the menu (or by creating a new branch).
+On the command line, switching to another already existing branch is done with the `git checkout` [command](https://git-scm.com/docs/git-checkout)
+
+The following screenshot shows how to switch from the current (`main`) branch to the newly created `imaginary-animals` branch:
+![git-checkout.png](./media/git-checkout.png)
+  ### Note
+  Don't forget to do a `git fetch` beforehand to retrieve the information about the branch that was created on the remote repository.
+
+To create a new branch, use the `git branch` [command](https://git-scm.com/docs/git-branch). This will create a new branch *in the local repository only*. 
+The new branch will be based on the current branch. But the new branch will not be *checked out* (i.e. you will remain on the current branch). You will
+need to do a `git checkout` to switch to the new branch, as shown in the following screenshot:
+![git-branch.png](./media/git-branch.png)
+
+The frequently used shortcut to create a new branch and to perform the checkout at once relies on adding the `-b`option to `git checkout`followed by the new branch name, as
+shown in the screenshot below:
+![git-checkout-branch.png](./media/git-checkout-branch.png)
+  ### Note
+  Before creating the second branch, we did a `git checkout` to return to the `imaginary-animals` branch. The `imaginary-animals-lotr` and `imaginary-animals-creepy`
+  branches are two "children" of the same parent branch (`imaginary-animals`).
+
+Using `git branch` without any arguments will display the list of branches in the local repository. Adding the `-a` option will also add what remote branches
+are currently known to your local repository, as shown in the screenshot below:
+![git-branch-list.png](./media/git-branch-list.png)
+
+
+
+
+
+
+
+
+
+