You will find two similar features inside of all Shared Cloud and Reseller Plan cPanel Accounts: MultiPHP and Select PHP Version.
How do I know which version I should use? Should I use MultiPHP?
We advise using only the "Select PHP Version" feature unless you need to have a specific version of PHP for a specific site.
Some use cases are when you want to run a newer version of PHP for most of your sites but you have one site that requires an older version of PHP. We'd advise using the "Select PHP Version" feature to set the newer version and then "MultiPHP" to choose the older version of PHP for only that site that requires an older version.
Select PHP Version
The feature in your cPanel > Select PHP Version is the default tool used to choose the PHP version for your account. The setting chosen in this area will apply to the whole account by default including websites, cron jobs, and the command line. With this tool you can choose the version of PHP as well as set many of the options for that version such as maximum upload file size, maximum post size, maximum execution time, and the memory_limit per PHP process.
The "Select PHP Version" feature does not have the ability to set a version of PHP per folder or per domain. If you need to choose a specific version for a specific site or folder you will want to use the MultiPHP feature also found in your cPanel. If the version in Select PHP Version does not match the ALT-PHP version chosen in MultiPHP it will not work properly.
The feature in your cPanel > MultiPHP will permit you to set a PHP version on a per-domain or per-folder basis for your account. The settings chosen within this area of the cPanel will override the version chosen in the 'Select PHP Version' area of your cPanel.
If you see "inherited" to the right of a version listed in MutliPHP that means that the PHP version for that domain is handled via cPanel -> Select PHP Version.
You will, for most versions of PHP, find two options listed within the MultiPHP tool. For example when it comes to PHP version 7.0 you will find these versions: 'alt-php70' and 'ea-php70'.
"alt-php" vs "ea-php"
"alt-php" is the version of PHP that is provided to us by CloudLinux that is selectable by the "Select PHP Version" feature in your cPanel. The settings in the "MultiPHP INI Editor" will not apply to any version of PHP that starts with "alt-php". To change the PHP features and options of any "alt-php" version you will need to select that version in the "Select PHP Version" feature and make the changes there. You will want the version chosen in "MultiPHP" to match the version in "Select PHP Version" for the settings to apply properly.
"ea-php" is the version of PHP that is provided to us by cPanel and is not available in the "Select PHP Version" feature in your cPanel. The settings in the "MultiPHP INI Editor" will apply to any version of PHP that starts with "ea-php". No settings from the "Select PHP Version" feature of your cPanel will apply to any "ea-php" version.