Zeek, initially known as Bro, stands as the premier platform for monitoring network security. It is an adaptable, open-source solution driven by those dedicated to defense in the cybersecurity realm. With its origins tracing back to the 1990s, the project was initiated by Vern Paxson to gain insights into activities on university and national laboratory networks. In late 2018, to acknowledge its growth and ongoing advancements, the leadership team transitioned the name from Bro to Zeek. Unlike conventional security tools such as firewalls or intrusion prevention systems, Zeek operates passively by residing on a sensor, which can be a hardware, software, virtual, or cloud-based platform, that discreetly monitors network traffic. By analyzing the data it collects, Zeek generates concise, high-quality transaction logs, file contents, and customizable outputs that are well-suited for manual examination on storage devices or through more user-friendly applications like security information and event management (SIEM) systems. This unique approach allows for a deeper understanding of network activities without interfering with the traffic itself.