Final answer:
The correct term that describes the process of improving security in a Network Operating System (NOS) is Hardening.
Step-by-step explanation:
The correct term that describes the process of improving security in a Network Operating System (NOS) is Hardening. Hardening refers to the process of strengthening the security measures of a system or network to minimize vulnerabilities and protect against unauthorized access or attacks.
This process involves implementing various security measures such as configuring firewalls, enabling encryption, applying patches and updates, setting up access controls, and disabling unnecessary services or features.
For example, in the case of a NOS like Windows Server, hardening can involve configuring the firewall rules to allow only specific network traffic, enabling encryption protocols such as Secure Sockets Layer (SSL) or Transport Layer Security (TLS), and regularly updating the system with the latest security patches.