If any of these items are highlighted in red then please take actions to correct them. Failure to do so could lead to your Joomla installation not functioning correctly.

These settings are recommended for PHP in order to ensure full compatibility with Joomla.
However, Joomla will still operate if your settings do not quite match the recommended

In order for Joomla to function correctly it needs to be able to access or write to certain files or directories. If you see "Unwriteable" you need to change the permissions on the file or directory to allow Joomla to write to it.