Whilst you will see a warning on the Home Dashboard when your website's Joomla! CMS is out of date, you won't see a similar such warning about PHP or MySQL. 1
And for this reason, you should frequently check which versions of these important web applications are being used by your server, and whether they are the latest version and release compatible with your Joomla! CMS.
You could visit the Hosting Control Panel providing by your hosting provider to check which versions, but it is arguably quicker and easier to check this screen instead.
We tell you how to check what is the latest available release in our Web Hosting Environment article.
And post updates in JOOMLERS.UK News when new releases are published.
1 This guide assumes your website is being hosted on a Linux server.
SYSTEM INFORMATION SCREEN
When you open the System Information screen you will see several tabs - shown here.
And under the System Information tab, a summary of the web applications (and their versions).
We have highlighted the ones you should keep a close eye on.
These links will help you compare the listed version of Joomla! CMS, PHP and MySQL 1 with the known latest available release.