Which feature restricts the applications that can run on servers and manages their interactions?

The feature that effectively restricts the applications that can run on servers and manages their interactions is server lockdown. This approach is designed to enhance security by allowing only pre-approved applications to execute, thereby minimizing the attack surface. By implementing server lockdown, organizations can enforce strict control over the environment, ensuring that only trusted applications and processes are permitted to communicate and operate.

In this context, server lockdown not only prevents unauthorized software from running but also helps manage how those approved applications interact with system resources and each other, thus significantly enhancing the security posture of the server environment. This proactive restriction reduces the possibility of malicious software exploiting vulnerabilities in unapproved applications.

Other options, while related to server security, do not precisely address the same function as server lockdown. For instance, server policies may define broader operational parameters and configurations, but they do not inherently restrict applications in the same manner. Application whitelisting is indeed a related practice used to allow only specific applications, but it doesn't encompass the comprehensive management of interactions as server lockdown does. Network segmentation focuses on dividing networks into segments to enhance security and control traffic, which, while important, does not directly relate to restricting applications on a server.