Glossary

Building your knowledge, one term at a time.
  • Network Attached Storage (NAS)

    Network Attached Storage (NAS) is a dedicated device that provides shared file storage over a network. Instead of plugging a drive into one computer, a NAS connects to your switch or router and presents folders that…

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  • Network Interface Card (NIC)

    A Network Interface Card (NIC) is a hardware component that connects a computer or other device to a network. Whether built into the motherboard or added as a plug-in card, a NIC provides the physical…

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  • Network Media

    Network media refers to the physical or wireless channels over which data travels between devices in a computer network. Whether it’s the copper wires carrying electrical signals, the hair-thin strands of glass conducting light pulses,…

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  • Network Time Protocol (NTP)

    The Network Time Protocol (NTP) keeps clocks on computers and devices in step so logs, security checks and schedules make sense. It works over UDP on port 123 and measures the delay to several time…

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  • Next-Generation Firewall (NGFW)

    A Next-Generation Firewall (NGFW) is a security device that goes beyond a traditional port and protocol firewall by inspecting traffic at the application layer and enforcing more precise policies. It can identify apps regardless of the port…

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  • NFC

    Near Field Communication (NFC) is a set of wireless standards that lets two electronic devices exchange small amounts of data when placed just a few centimetres apart. It relies on electromagnetic fields to transfer information…

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  • NIST

    NIST is the National Institute of Standards and Technology, a part of the US Department of Commerce that develops measurement standards, guidelines and best practices. In cyber security it publishes the NIST Cybersecurity Framework and…

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  • Non-Blind Spoofing

    Non-blind spoofing is source-address forgery where the attacker can see the target’s replies in real time, so they can keep a two-way exchange in step. It is an on-path situation where the attacker sits on…

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  • Non-Validated Input

    Non-validated input is any data a system or application accepts without checking that it meets expected criteria such as format, length or type. Because the data is not examined before use, the application may encounter…

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  • Normalization

    Normalization is the process of putting data into a consistent, standard form so systems can store, compare and analyse it reliably. In databases, it means structuring tables to reduce duplication and update problems, for example…

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  • NTFS

    NTFS (New Technology File System) is Microsoft’s modern file system for Windows, designed for large disks and reliable storage. It keeps a Master File Table (MFT) that records every file and folder, and it journals…

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  • OAuth

    OAuth (Open Authorisation) is a protocol that lets a user grant a third party limited access to their data on another service without sharing their password. When you allow an app to read your contacts…

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  • Obfuscation

    Obfuscation is the practice of making information or code harder to understand at a glance. In software it hides implementation details to slow reverse engineering, for example by renaming identifiers to meaningless labels, encrypting strings, inserting…

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  • Offline Identity

    Offline identity is the information and credentials used to confirm someone’s identity in person. It includes documents such as passports, driving licences and birth certificates, alongside biometric traits like fingerprints or facial recognition. It is…

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  • Online Identity

    Online identity refers to the collection of data and credentials used to verify someone’s identity in digital environments. It includes usernames, passwords, email addresses, digital certificates and biometric identifiers. An individual’s online identity enables access…

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  • Open Mail Relay

    An open mail relay is an SMTP server that forwards email from anyone on the internet to any destination without authentication or meaningful restrictions. This behaviour was common in the early days of email but…

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  • Operating System

    An operating system (OS) is the core software that sits between hardware and applications. It starts the computer, loads drivers, and presents a stable platform so programs do not need to talk to chips directly.…

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  • OSI Reference Model

    The OSI Reference Model, or Open Systems Interconnection model, is a model that breaks down network communication into seven distinct layers. Developed by the International Organisation for Standardisation (ISO) in the early 1980s, the OSI…

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  • OWASP

    OWASP, the Open Worldwide Application Security Project, is a global non-profit community that publishes free guidance, standards and tools to help make software more secure. Its resources are widely used by developers, testers and security…

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  • PaaS

    Platform as a Service, or PaaS, is a cloud model that provides a managed environment for building, running and scaling applications without asking developers to maintain servers, operating systems or low level networking. The provider…

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