The Symfony2 profiler
The profiler information is collected and stored within the cache directory and stored in simple serialized data files. You can access them by the token generated, and they will persist as long as the file exists in the cache folder.
The Web Debug Toolbar is displayed only in the development mode. If you run your configuration in the production mode, it will not be displayed, and it is not recommended to change this setting.
After you log in, you should notice changes in the form section and in the database section. Click on the form section to see something similar to this:
This is one of the most useful screens while debugging to check what went wrong with the form object. In the middle column, you have exposed all the form widgets that have been applied to. In the right column, you have information about the passed objects, model, and submitted data.
This section is most useful while checking why the form did not validate properly. So let's try to generate some errors...