CageFS is a virtualized file system and a component of CloudLinux, a Linux distribution designed for shared hosting environments. It is a critical part of the CloudLinux OS architecture and provides a secure environment for hosting providers and their customers.

Here's a breakdown of what CageFS does:

1. Isolation: CageFS isolates each user account on a shared server, creating a virtualized environment that prevents one user from seeing or accessing the files and processes of other users. This isolation enhances security and stability in a shared hosting environment.

2. Virtual File System: CageFS creates a virtual file system for each user, which means that when a user logs in, they see their own set of files and directories. Even if a user has shell access, they won't be able to navigate outside of their own "cage."

3. Restrictions: CageFS applies a set of restrictions to each user's environment. This includes limiting access to system files and directories, as well as preventing users from viewing processes that don't belong to them.

4. Preventing Exploits: CageFS helps mitigate the impact of security vulnerabilities in web applications. Even if an attacker gains access to a user's account, they will be confined within the user's cage and won't be able to access other users' data or system files.

5. Compatibility with Control Panels: CageFS is compatible with popular control panels like cPanel, Plesk, DirectAdmin, and more. It seamlessly integrates with these control panels, allowing hosting providers to easily enable and manage CageFS for their customers.

6. Enhanced Security: By isolating users and restricting their access, CageFS provides an additional layer of security for shared hosting environments. It helps protect against privilege escalation attacks and other security risks.

7. Resource Limitations: CageFS can be used in conjunction with other CloudLinux features like LVE (Lightweight Virtual Environment) to set resource limits for each user. This ensures that one user's activities don't negatively impact the performance of others on the server.

Overall, CageFS is a powerful tool for enhancing the security and stability of shared hosting environments. It's especially valuable in scenarios where multiple users or websites are hosted on the same server, as it prevents one compromised account from affecting others.