Protective measures prescribed to meet the security requirements (i.e., confidentiality, integrity, and availability) specified for an information system. Safeguards may include security features, man

Safeguards are protective measures, including security features, management constraints, personnel security, and physical security elements, implemented to protect an information system and its information. They are designed to meet specific security requirements related to confidentiality, integrity, and availability, and are indeed synonymous with security controls and countermeasures.

A subsystem is a component of a larger system, not a general term for protective measures.

Tailored security refers to the process of adapting security controls to a specific system's environment, not the protective measures themselves.

A control baseline is a set of minimum security controls recommended for a system, but it's the list of controls, not the generic term for protective measures.