CREST Practitioner Security Analyst (CPSA) Practice 2025 - Free CPSA Practice Questions and Study Guide

Nagios is best described as an open-source system monitoring service. This designation highlights its primarily community-driven nature, where users can contribute to its development, share plugins, and customize the software to suit their specific needs. Nagios excels in monitoring the health and performance of various networked services, servers, and infrastructure, providing alerts and information to system administrators when issues arise.

Being open-source means that it is freely available for users to download, use, and modify, which has contributed to its widespread adoption across various industries. The flexibility of Nagios, combined with its ability to integrate with other tools and systems, makes it a valuable asset for maintaining operational uptime and system reliability.

This differentiation from the other descriptions emphasizes Nagios' role in proactive monitoring rather than account management or file transfer functionality, which are not core to its purpose.