A vulnerability scanner is a software tool designed to identify security weaknesses in computer systems, networks, and applications. By scanning for known vulnerabilities, such as outdated software or misconfigurations, these tools help organizations assess their security posture and prioritize remediation efforts. These scanners can be automated to run regularly, providing continuous monitoring and reporting. Common types of vulnerability scanners include network scanners, web application scanners, and database scanners. Popular examples include Nessus, Qualys, and OpenVAS, which are widely used in the cybersecurity industry to enhance overall security measures.