The FREE Cybersecurity Glossary by Thor Pedersen!

External router: A device that connects networks together and facilitates data transfer between them. Primarily used for connecting to networks outside an organization's primary network, it serves as a gateway for data packets traveling between these disparate networks, controlling and directing traffic based on routing tables and protocols.

External storage: Any storage medium that is not directly integrated into the main device. This can include hard drives, solid-state drives, USB flash drives, memory cards, or network-attached storage devices. External storage allows for increased data storage capacity portability and often serves as a method for data backup.

Extranet: A private network that uses internet technology and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses. It can be viewed as part of a company's intranet that is extended to users outside the company, offering controlled access while maintaining privacy and security.

Fail-open: A fail-open design refers to a security system's configuration that, in the event of a system failure, defaults to an "open" state, allowing all traffic or access. This approach prioritizes availability and continuity of operations over strict access control, often used in scenarios where service disruption is unacceptable despite the potential security risks it could introduce. This could also be doors that fail-open in case of an emergency, to allow for safe egress from a building.

Fail-Over (Fail-over): A backup operational mode in which the functions of a system component (such as a processor, server, network, or database) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled downtime. Fail-over helps maintain high availability and reliability by ensuring that services continue to operate in the event of a component failure. This process can occur automatically without human intervention or can be manually triggered.

Failsafe: A fail-safe design ensures that in the event of a system failure or malfunction, the system will default to a safe or minimal risk condition to prevent or minimize harm or damage. Failsafe mechanisms are critical in various industries and technologies, such as in aviation, automotive safety systems, and nuclear power plants, where a failure could have severe consequences. In computing, a failsafe may involve switching to a backup system or mode of operation that maintains service continuity at a reduced capacity.