CentOS中PHP包名称里的rh-是什么含义？

Hey there! Let's break down that rh prefix you're seeing on the last three PHP-PDO packages from your yum search php-pdo output.

• The rh stands for Red Hat Software Collections (often shortened to SCL).
• Here's the core idea: RHEL/CentOS systems stick with older, stable software versions (like the PHP 5.4 and 5.5 packages you spotted) as the default—this keeps system tools and built-in dependencies reliable. But if your applications need a newer PHP release, SCL lets you install these updated rh- prefixed packages without overwriting the system's default PHP installation.
• This means you can run both the old, system-wide PHP and the newer rh- version side by side. To use the rh- package, you just need to enable the collection temporarily (for example, running scl enable rh-php74 bash switches your current shell to use PHP 7.4) or configure it for specific apps.
• The first unlabeled package is likely the default system PHP package from your distro's base repo, matching the pre-installed PHP version of your OS.

内容的提问来源于stack exchange，提问作者user9719859