Robots TXT File
Prior to Joomla! 3.3.0 the robots.txt file distributed with the Joomla! CMS was configured slightly differently to later versions of the Joomla! CMS.
When Joomla! 3.3.0 was released, the configuration of the robots.txt file changed to improve the performance of Joomla! websites in mobile search results.
The change resulted in search bots no longer being denied access to the following directories:
Why you should check your website's ROBOTS.TXT file
Without access to the above directories the search engine bots cannot see that your website is mobile-friendly.
Why should you check?
If your website started life using a version of the Joomla! CMs prior to Joomla! 3.3.0, you will need to manually change the robots.txt file.
Reason: the robots.txt file was not automatically updated when updating from an older version of Joomla!
How can you change the robots.txt file?
You can edit the robots.txt file via the File Manager screen of your Hosting Control Panel.