Final answer:
A Nessus scan report identifies vulnerabilities by performing active scans on the targeted system's network and individual hosts. It uses a database of known vulnerabilities to match and identify signs of potential weaknesses in the system.
Step-by-step explanation:
A Nessus scan report identifies vulnerabilities by performing active scans on the targeted system's network and individual hosts. It uses a database of known vulnerabilities to match and identify signs of potential weaknesses in the system, such as open ports, misconfigurations, or outdated software versions. Each vulnerability is assigned a unique identifier and severity level, allowing system administrators to prioritize and address the most critical ones first.