[Testing] Reorganize the introduction of some articles

testing.rst

@@ -5,14 +5,38 @@ Whenever you write a new line of code, you also potentially add new bugs.
 To build better and more reliable applications, you should test your code
 using both functional and unit tests.
 
-.. _testing-installation:
+Symfony integrates with an independent library called `PHPUnit`_ to give you a
+rich testing framework. This article covers the PHPUnit basics you'll need to
+write Symfony tests. To learn everything about PHPUnit and its features, read
+the `official PHPUnit documentation`_.
+
+Types of Tests
+--------------
+
+There are many types of automated tests and precise definitions often
+differ from project to project. In Symfony, the following definitions are
+used. If you have learned something different, that is not necessarily
+wrong, just different from what the Symfony documentation is using.
+
+`Unit Tests`_
+    These tests ensure that *individual* units of source code (e.g. a single
+    class) behave as intended.
+
+`Integration Tests`_
+    These tests test a combination of classes and commonly interact with
+    Symfony's service container. These tests do not yet cover the fully
+    working application, those are called *Application tests*.
+
+`Application Tests`_
+    Application tests (also known as functional tests) test the behavior of a
+    complete application. They make HTTP requests (both real and simulated ones)
+    and test that the response is as expected.
 
-The PHPUnit Testing Framework
------------------------------
+.. _testing-installation:
+.. _the-phpunit-testing-framework:
 
-Symfony integrates with an independent library called `PHPUnit`_ to give
-you a rich testing framework. This article won't cover PHPUnit itself,
-which has its own excellent `documentation`_.
+Installation
+------------
 
 Before creating your first test, install ``symfony/test-pack``, which installs
 some other packages needed for testing (such as ``phpunit/phpunit``):
@@ -44,28 +68,6 @@ your test into multiple "test suites").
     missing, you can try running the recipe again using
     ``composer recipes:install phpunit/phpunit --force -v``.
 
-Types of Tests
---------------
-
-There are many types of automated tests and precise definitions often
-differ from project to project. In Symfony, the following definitions are
-used. If you have learned something different, that is not necessarily
-wrong, just different from what the Symfony documentation is using.
-
-`Unit Tests`_
-    These tests ensure that *individual* units of source code (e.g. a single
-    class) behave as intended.
-
-`Integration Tests`_
-    These tests test a combination of classes and commonly interact with
-    Symfony's service container. These tests do not yet cover the fully
-    working application, those are called *Application tests*.
-
-`Application Tests`_
-    Application tests test the behavior of a complete application. They
-    make HTTP requests (both real and simulated ones) and test that the
-    response is as expected.
-
 Unit Tests
 ----------
 
@@ -1193,7 +1195,7 @@ Learn more
     /components/css_selector
 
 .. _`PHPUnit`: https://phpunit.de/
-.. _`documentation`: https://docs.phpunit.de/
+.. _`official PHPUnit documentation`: https://docs.phpunit.de/
 .. _`Writing Tests for PHPUnit`: https://docs.phpunit.de/en/10.5/writing-tests-for-phpunit.html
 .. _`PHPUnit documentation`: https://docs.phpunit.de/en/10.5/configuration.html
 .. _`unit test`: https://en.wikipedia.org/wiki/Unit_testing

testing/end_to_end.rst

@@ -1,41 +1,35 @@
 End-to-End Testing
 ==================
 
-    The Panther component allows to drive a real web browser with PHP to create
-    end-to-end tests.
+End-to-end tests simulate how real users interact with your application through
+a browser. They focus on verifying your user interface and the outcomes of user
+actions (like confirming that clicking a button sends an email).
+
+Unlike :ref:`application tests <functional-tests>`, these tests run in a real
+browser that can work in headless mode (without a graphical interface) for CI
+environments or with a graphical interface for debugging.
+
+Symfony provides a component called **Panther** to run end-to-end tests. Panther
+lets you run tests in a real browser and offers unique features not available in
+other test types:
+
+* Taking screenshots at any point during the test;
+* Executing JavaScript on your pages;
+* Supporting everything Chrome or Firefox does;
+* Simpler testing of real-time applications (e.g. WebSockets, Server-Sent Events with Mercure).
 
 Installation
 ------------
 
+Before creating and running your first end-to-end tests, run the following command
+to install the needed dependencies:
+
 .. code-block:: terminal
 
     $ composer require symfony/panther
 
 .. include:: /components/require_autoload.rst.inc
 
-Introduction
-------------
-
-End to end tests are a special type of application tests that
-simulate a real user interacting with your application. They are
-typically used to test the user interface (UI) of your application
-and the effects of these interactions (e.g. when I click on this button, a mail
-must be sent). The difference with functional tests detailed above is
-that End-to-End tests use a real browser instead of a simulated one. This
-browser can run in headless mode (without a graphical interface) or not.
-The first option is convenient for running tests in a Continuous Integration
-(CI), while the second one is useful for debugging purpose.
-
-This is the purpose of Panther, a component that provides a real browser
-to run your tests. Here are a few things that make Panther special, compared
-to other testing tools provided by Symfony:
-
-* Possibility to take screenshots of the browser at any time during the test
-* The JavaScript code contained in webpages is executed
-* Panther supports everything that Chrome (or Firefox) implements
-* Convenient way to test real-time applications (e.g. WebSockets, Server-Sent Events
-  with Mercure, etc.)
-
 Installing Web Drivers
 ~~~~~~~~~~~~~~~~~~~~~~