What is the purpose of hardening systems?

Hardening involves removing unnecessary services, closing unused ports, disabling default accounts, and applying least-privilege configurations - all of which directly reduce the attack surface by eliminating unnecessary exposure points that attackers could exploit to gain unauthorized access.

Creating logic that triggers alerts on anomalies describes the function of a SIEM or intrusion detection system, not system hardening.

Identifying vulnerabilities within an operating system is the purpose of vulnerability scanning or assessment tools, which is a separate process from hardening.

Analyzing attacks to identify threat actors and points of entry describes digital forensics and threat intelligence activities, not system hardening.