Final answer:
A vulnerability scanner is a tool used by penetration testers and system administrators to identify security vulnerabilities and ensure configuration compliance, particularly in web servers.
Step-by-step explanation:
The subject of this question is a tool often utilized by penetration testers and system administrators for checking security vulnerabilities and configuration compliance in network systems, particularly in web servers. This tool, commonly known as a vulnerability scanner, is designed to automate the process of identifying potential security risks that could be exploited by attackers. Its utility extends beyond penetration testing; it's also used by admins to confirm that the settings of their servers conform to the desired security policies.
Vulnerability scanners essentially assess the defense mechanisms of a network or system and produce reports detailing possible points of failure. These reports can then guide the strengthening of the system's security posture. Such scanners are integral to maintaining a robust network security strategy, serving as both a preventative and diagnostic tool for organizations.