CloudLinux OS offers several different editions, including CloudLinux OS Shared and CloudLinux OS Shared PRO. Here are the main differences between the two:

1. Resource Allocation:

   • CloudLinux OS Shared: This edition is designed for shared hosting environments. It includes features like Lightweight Virtual Environment (LVE) and CageFS to provide isolation between users on a shared server. Each user gets allocated a specific amount of resources (CPU, memory, etc.) to ensure fair usage.

   • CloudLinux OS Shared PRO: Shared PRO builds upon the features of CloudLinux OS Shared and includes additional optimizations and tools to further enhance the performance and security of shared hosting environments.

2. Additional Features (Shared PRO):

   • CloudLinux OS Shared PRO may include additional features that are not available in the standard Shared edition. These could include advanced security options, performance optimizations, and additional management tools.

3. Pricing:

   • CloudLinux OS Shared PRO may be priced differently from the standard Shared edition due to the additional features and capabilities it offers.

4. Support and Updates:

   • Both editions of CloudLinux OS likely come with standard support and regular updates. However, the level of support and the frequency of updates may vary.

5. Suitability:

   • CloudLinux OS Shared: This edition is suitable for hosting providers and businesses that operate shared hosting environments and want to ensure fair resource allocation and isolation between users.

   • CloudLinux OS Shared PRO: Shared PRO is likely aimed at hosting providers and businesses that want additional performance and security optimizations in their shared hosting environments.

6. Specific Features:

   • Without specific release notes or updates beyond September 2021, it's not possible to provide a comprehensive list of the exact features that differentiate CloudLinux OS Shared and Shared PRO. For the most accurate and up-to-date information, I recommend checking the CloudLinux website or contacting CloudLinux support directly.

Please note that the information provided here is based on the state of CloudLinux OS as of September 2021. There may have been updates or changes to the offerings since then. Always refer to the official CloudLinux documentation and resources for the most current information.