Secure Socket Layer (SSL): A cryptographic protocol designed to provide secure communications over a computer network. SSL uses a combination of public key and symmetric key encryption to secure a connection between two machines, typically a web server and a client, over the internet. It was widely used for securing data transfer, ensuring the privacy and integrity of information, and verifying the identity of parties involved in the communication through the use of digital certificates. SSL has been superseded by Transport Layer Security (TLS), an updated and more secure version of the protocol, and while the term SSL is still commonly used, most underlying systems actually use TLS.

Secure State: A condition in which an information system is safeguarded against unauthorized access, use, disclosure, disruption, modification, or destruction. It plays a vital role in security planning and risk management. Examples include maintaining the integrity and confidentiality of a computer system, network, or facility.

Secure Subsystem: A subsystem of an information system designed to safeguard against unauthorized access, use, disclosure, disruption, modification, or destruction. It is integral to security architecture and includes components like firewalls, intrusion detection systems, and encryption algorithms.

Securing network components: The practice of implementing security measures on network components, such as routers, firewalls, and servers, to protect against unauthorized access and attacks. This is used to protect the confidentiality, integrity, and availability of networked systems and data. For example, a router may be configured with a firewall to block malicious traffic or a server may be configured with access controls to prevent unauthorized access.

Security administrator: A professional responsible for managing an organization's IT security policies and procedures. Security administrators oversee the implementation of security solutions, monitor for threats, and ensure that networks and data remain secure against unauthorized access and breaches.

Security analyst: A professional who is responsible for analyzing security risks and vulnerabilities and developing solutions to protect against them. They may work in a variety of industries, such as finance, healthcare, and government. For example, a security analyst at a bank may analyze network logs to identify potential threats, or a security analyst at a hospital may develop policies to protect patient data.