IT & Cybersecurity Glossary | Key Terms Explained

AES (Advanced Encryption Standard)

A specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST)

The Simple Definition:

A highly secure encryption method used to protect sensitive data

API (Application Programming Interface)

A set of definitions and protocols for building and integrating application software

The Simple Definition:

A way for different software programs to communicate with each other

APT (Address Resolution Protocol)

A communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address

The Simple Definition:

The system that connects IP addresses to physical computer addresses on a network

Active Directory

A directory service developed by Microsoft for Windows domain networks that authenticates and authorizes users and computers in a Windows domain network

The Simple Definition:

Microsoft's system for managing users, computers, and permissions in a business network

Advanced Persistent Threat (APT)

A prolonged and targeted cyber attack in which an intruder establishes an undetected presence in a network to steal sensitive data over an extended period

The Simple Definition:

A sophisticated, long-term cyber attack where hackers secretly remain inside your systems for months or years to steal information

Air Gap

A security measure that involves ensuring a computer or network is physically isolated from unsecured networks, such as the public internet

The Simple Definition:

Physically separating a secure computer from the internet for maximum protection

Artificial Intelligence (AI)

The simulation of human intelligence processes by machines, especially computer systems

The Simple Definition:

Technology that enables computers to mimic human thinking and learning

Asymmetric Encryption

A type of encryption where keys come in pairs (public and private) and what one key encrypts, only the other can decrypt

The Simple Definition:

A security method using two different keys - one public (shared) and one private (secret)

Authentication

The process of verifying the identity of a user, system, or entity before allowing access to resources

The Simple Definition:

The way computers confirm you are who you say you are, like when you enter a password

BYOD (Bring Your Own Device)

A policy allowing employees to bring personally owned devices to their workplace and use those devices to access company information and applications

The Simple Definition:

Allowing employees to use their personal phones, tablets, or laptops for work purposes

Backdoor

A method of bypassing normal authentication in a computer system, network, or algorithm

The Simple Definition:

A secret way into a computer system that avoids the normal security checks, like an unlocked side door on a building

Backup

A copy of data taken and stored elsewhere as a precaution against loss or damage to the original

The Simple Definition:

A spare copy of your important files kept safe in case something happens to the originals

Bandwidth

The maximum rate of data transfer across a given path in a network

The Simple Definition:

How much information can travel through your internet connection at once, like the width of a water pipe

Blockchain

A system of recording information in a way that makes it difficult or impossible to change, hack, or cheat the system

The Simple Definition:

A digital ledger that records transactions across many computers so no single record can be altered retroactively

Botnet

A network of private computers infected with malicious software and controlled without the owners' knowledge

The Simple Definition:

A collection of infected computers controlled by hackers to perform tasks without their owners knowing

Breach

An incident in which data, computer systems, or networks are accessed without authorization

The Simple Definition:

When hackers successfully break into a system and potentially access sensitive information

Brute Force Attack

A trial-and-error method used to obtain information such as a password or PIN

The Simple Definition:

Repeatedly trying different passwords until finding the correct one, like trying every possible key to unlock a door

Bug

An error, flaw, or fault in a computer program that causes it to produce an incorrect or unexpected result

The Simple Definition:

A mistake in computer code that causes something to work incorrectly

Business Continuity

The capability of an organization to continue the delivery of products or services following a disruptive incident

The Simple Definition:

Plans and systems that keep a business running when something goes wrong

CAPTCHA

A type of challenge-response test used to determine whether the user is human

The Simple Definition:

Those puzzles on websites that ask you to identify traffic lights or type distorted text to prove you're not a robot

CDN (Content Delivery Network)

A geographically distributed network of proxy servers and their data centers that provides high availability and performance by distributing the service spatially relative to end-users

The Simple Definition:

A network of servers around the world that delivers web content to users based on their geographic location

CISA (Cybersecurity and Infrastructure Security Agency)

The United States federal agency responsible for improving cybersecurity across all levels of government and critical infrastructure

The Simple Definition:

The U.S. government agency responsible for protecting critical infrastructure from cyber threats

CSIRT (Computer Security Incident Response Team)

A group of IT security professionals responsible for receiving, reviewing, and responding to computer security incident reports and activity

The Simple Definition:

A team of experts who respond to cybersecurity incidents and breaches

CTI (Cyber Threat Intelligence)

Evidence-based knowledge, including context, mechanisms, indicators, implications, and action-oriented advice about existing or emerging threats

The Simple Definition:

Information about current and potential cyber threats that helps organizations make better security decisions

CVE (Common Vulnerabilities and Exposures)

A list of publicly disclosed computer security flaws each with an identification number, a description, and at least one public reference

The Simple Definition:

A standardized system for identifying and cataloging known security vulnerabilities in software

Cloud Computing

The delivery of computing services over the internet rather than from local servers

The Simple Definition:

Using internet-based services to store and access programs and data instead of your own computer

Cold Site

A backup facility that has the necessary electrical and physical components of a computer system, but does not have the computer equipment in place

The Simple Definition:

A backup location with basic infrastructure but no computers, requiring equipment to be brought in during a disaster

Compliance

Adhering to established guidelines, specifications, or regulations

The Simple Definition:

Following the rules and requirements that apply to your business, especially regarding data protection

Credential Stuffing

A type of cyberattack where stolen account credentials, typically consisting of username and password pairs, are used to gain unauthorized access to user accounts through large-scale automated login requests

The Simple Definition:

Using stolen usernames and passwords from one website to try to log into other websites

Cryptography

The practice and study of techniques for secure communication in the presence of adversaries

The Simple Definition:

The science of coding and decoding messages to keep them secure from unauthorized access

Cybersecurity

The practice of protecting systems, networks, and programs from digital attacks

The Simple Definition:

Protecting computers, networks, and data from harmful attacks, damage, or unauthorized access

DDOS Protection

Services and techniques used to defend against distributed denial-of-service attacks by absorbing the flood of traffic, deflecting it, or degrading it

The Simple Definition:

Systems that prevent websites from being overwhelmed by massive amounts of fake traffic

DDoS (Distributed Denial of Service)

An attack that overwhelms a system's resources, making it unavailable to users

The Simple Definition:

When attackers flood a website or service with so much traffic that it crashes or becomes unusable

DKIM (DomainKeys Identified Mail)

An email authentication method designed to detect email spoofing

The Simple Definition:

A system that helps prove emails really came from the sender they claim to be from

DMZ (Demilitarized Zone)

A physical or logical subnetwork that contains and exposes an organization's external-facing services to an untrusted network

The Simple Definition:

A buffer zone between your secure internal network and the unsafe outside world

DNS (Domain Name System)

A hierarchical and decentralized naming system for computers, services, or any resource connected to the Internet or a private network

The Simple Definition:

The phone book of the internet that turns website names into the numeric addresses computers use

DNS Poisoning

A type of cyberattack that exploits vulnerabilities in the domain name system to divert internet traffic away from legitimate servers and towards fake ones

The Simple Definition:

Corrupting DNS servers to redirect users to fake websites instead of the real ones they requested

Data At Rest

Data that is stored on a device or backup medium and is not actively being accessed or transmitted

The Simple Definition:

Information stored on your computers, servers, or backup devices that isn't currently being used

Data Breach

A confirmed incident involving the unauthorized access of data

The Simple Definition:

When sensitive information gets stolen or exposed to unauthorized people

Data Encryption

The process of converting information or data into a code, especially to prevent unauthorized access

The Simple Definition:

Scrambling your data so only people with the right key can read it

Data In Transit

Data actively moving from one location to another, whether across the internet or through a private network

The Simple Definition:

Information that's actively traveling between devices or across networks

Data Lake

A centralized repository that allows you to store all your structured and unstructured data at any scale

The Simple Definition:

A vast storage system that holds raw data in its original format until needed

Data Loss Prevention (DLP)

A strategy for ensuring that end users do not send sensitive or critical information outside the corporate network

The Simple Definition:

Tools that stop sensitive information from leaving your company's network

Data Mining

The process of discovering patterns in large data sets involving methods at the intersection of machine learning, statistics, and database systems

The Simple Definition:

Analyzing large amounts of information to find useful patterns and connections

Data Sovereignty

The concept that information which has been converted and stored in binary digital form is subject to the laws of the country in which it is located

The Simple Definition:

Rules determining which country's laws apply to data based on where it's stored

Data Warehousing

A system used for reporting and data analysis, considered a core component of business intelligence

The Simple Definition:

A large storage system specifically designed for analyzing and reporting business data

Database

An organized collection of structured information or data, typically stored electronically

The Simple Definition:

A digital filing cabinet where information is stored in an organized way

Digital Certificate

An electronic document used to prove the ownership of a public key

The Simple Definition:

An electronic ID card that proves a website or service is legitimate

Digital Forensics

The process of uncovering and interpreting electronic data to preserve evidence in a way that is suitable for presentation in a court of law

The Simple Definition:

The process of investigating digital devices to collect evidence of activities

Digital Signature

A mathematical scheme for verifying the authenticity of digital messages or documents

The Simple Definition:

An electronic fingerprint that confirms who created or sent a document

Disaster Recovery

A set of policies and procedures to enable the recovery or continuation of vital technology infrastructure and systems following a natural or human-induced disaster

The Simple Definition:

A plan for getting your IT systems back up and running after a major problem

EDR (Endpoint Detection and Response)

Security tools that focus on detecting and investigating suspicious activities on hosts and endpoints

The Simple Definition:

Advanced security software that monitors and responds to threats on computers and devices

Encryption

The method of converting information into a code to prevent unauthorized access

The Simple Definition:

Converting information into a secret code to keep it private

Endpoint

Any device connected to a network, such as laptops, smartphones, or servers

The Simple Definition:

Any device that connects to your network, like computers, phones, or tablets

Ethical Hacking

The practice of testing a computer system, network, or web application to find security vulnerabilities that a malicious hacker could exploit

The Simple Definition:

Legal hacking performed by security experts to find and fix vulnerabilities before criminals can exploit them

Exploit

A piece of software, data, or sequence of commands that takes advantage of a vulnerability to cause unintended behavior

The Simple Definition:

A way to take advantage of a security weakness in software

FTP (File Transfer Protocol)

A standard network protocol used for the transfer of files between a client and server on a computer network

The Simple Definition:

A method for sending files between computers over a network

False Positive

An alert or indication of a threat that turns out not to be an actual security issue

The Simple Definition:

A security alarm that goes off when there's actually no threat, like a smoke detector triggered by burnt toast

Fileless Malware

A type of malicious code that exists solely in memory, rather than on the hard drive

The Simple Definition:

Malicious software that operates entirely in memory without leaving traces on the hard drive

Firewall

A network security system that monitors and controls incoming and outgoing network traffic

The Simple Definition:

A security barrier between your network and the outside world that blocks unauthorized access

Fuzzing

A quality assurance and security testing technique that involves providing invalid, unexpected, or random data as inputs to a computer program

The Simple Definition:

Testing software by feeding it random or unexpected data to find security flaws

GDPR (General Data Protection Regulation)

A regulation in EU law on data protection and privacy for all individuals within the European Union

The Simple Definition:

European privacy laws that give people control over their personal data and how it's used

Geofencing

The use of GPS or RFID technology to create a virtual geographic boundary, enabling software to trigger a response when a mobile device enters or leaves a particular area

The Simple Definition:

A virtual boundary that can trigger actions when devices cross it

HIPAA

Health Insurance Portability and Accountability Act, a US law protecting sensitive patient health information

The Simple Definition:

U.S. laws that protect patient privacy and secure health information

HTTPS (Hypertext Transfer Protocol Secure)

An extension of HTTP used for secure communication over a computer network

The Simple Definition:

The secure version of the protocol that loads websites in your browser, indicated by a padlock icon

HTTPS Everywhere

A browser extension that encrypts communications with many major websites, making browsing more secure

The Simple Definition:

A tool that automatically switches websites from HTTP to encrypted HTTPS when available

Hacker

A person who uses computers to gain unauthorized access to data

The Simple Definition:

Someone who breaks into computer systems, either maliciously or to find and fix security problems

Honeypot

A decoy system designed to look like a legitimate part of the network but is actually isolated and monitored

The Simple Definition:

A trap set up to attract hackers to study their tactics or divert them from real systems

IAM (Identity and Access Management)

A framework of policies and technologies for ensuring that the right users have the appropriate access to technology resources

The Simple Definition:

Systems that control which users have access to which resources and what they can do with them

ICO (Initial Coin Offering)

A type of funding using cryptocurrencies, often a source of cybersecurity scams

The Simple Definition:

A fundraising method where new cryptocurrency projects sell tokens to early investors

IDS (Intrusion Detection System)

A device or software application that monitors a network for malicious activities or policy violations

The Simple Definition:

A security system that watches for suspicious activity on your network

IP Address

A unique numerical label assigned to each device connected to a computer network

The Simple Definition:

A unique address that identifies a device on the internet or a local network

IPS (Intrusion Prevention System)

A network security system that monitors network traffic for suspicious activity and takes preventative action to stop potential threats

The Simple Definition:

An advanced security system that not only detects network attacks but actively blocks them

IPsec (Internet Protocol Security)

A protocol suite for securing Internet Protocol communications by authenticating and encrypting each IP packet of a communication session

The Simple Definition:

A set of security protocols that protect information sent over the internet

ISP (Internet Service Provider)

An organization that provides services for accessing and using the internet

The Simple Definition:

The company that provides your internet connection

Identity Theft

The fraudulent acquisition and use of a person's private identifying information

The Simple Definition:

When someone steals your personal information to pretend to be you

IoT (Internet of Things)

The network of physical devices connected to the internet, collecting and sharing data

The Simple Definition:

Everyday objects connected to the internet, like smart thermostats or doorbell cameras

Jailbreak

The process of removing software restrictions imposed by the device manufacturer

The Simple Definition:

Removing limitations put on a device by its manufacturer to gain full access to the system

Kerberos

A computer network authentication protocol that works on the basis of tickets to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner

The Simple Definition:

A secure way for computers to verify each other's identities on untrusted networks

Key

In cryptography, a piece of information used to encrypt or decrypt data

The Simple Definition:

The secret code needed to unscramble encrypted information

Keylogger

A program that records the keystrokes on a computer

The Simple Definition:

Software that secretly records everything you type, including passwords

Kubernetes Security

Security practices specific to Kubernetes, an open-source container-orchestration system

The Simple Definition:

Security measures designed for systems that manage containerized applications

LAN (Local Area Network)

A computer network that interconnects computers within a limited area

The Simple Definition:

A network that connects computers in a small area like an office

Latency

The delay before a transfer of data begins following an instruction for its transfer

The Simple Definition:

The delay between when you request something online and when you receive it

Lateral Movement

The techniques that attackers use to progressively move through a network in search of key data and assets after gaining initial access

The Simple Definition:

How hackers move sideways through a network after breaking in, searching for valuable data

MFA (Multi-Factor Authentication)

A security system that requires more than one method of authentication

The Simple Definition:

A security measure requiring two or more verification methods to gain access, like a password plus a text message code

MITRE ATT&CK Framework

A globally accessible knowledge base of adversary tactics and techniques based on real-world observations

The Simple Definition:

A comprehensive guide to how hackers operate and attack systems, based on real incidents

MSSP (Managed Security Service Provider)

A company that provides outsourced monitoring and management of security devices and systems

The Simple Definition:

A specialized service provider that focuses on security monitoring and management for your business

Malware

Malicious software designed to damage, disrupt, or gain unauthorized access to a computer system

The Simple Definition:

Harmful software designed to damage or gain unauthorized access to your system, like viruses or spyware

Man-in-the-Middle Attack

An attack where the attacker secretly relays and possibly alters the communications between two parties who believe they are directly communicating with each other

The Simple Definition:

When an attacker secretly intercepts and potentially changes communications between two people

Managed Service Provider (MSP)

A company that remotely manages a customer's IT infrastructure and/or end-user systems on a proactive basis under a subscription model

The Simple Definition:

A company that handles your IT systems for you, monitoring and maintaining them for a monthly fee

Moving Target Defense

A security strategy that continuously changes the attack surface to increase uncertainty and complexity for attackers

The Simple Definition:

A defense strategy that constantly changes your system configuration to confuse attackers

NFT (Non-Fungible Token)

A cryptographic asset on a blockchain with unique identification codes and metadata that distinguish them from each other

The Simple Definition:

A unique digital item with verified ownership recorded on a blockchain

NGFW (Next-Generation Firewall)

A hardware or software-based network security system that is capable of detecting and blocking sophisticated attacks

The Simple Definition:

An advanced firewall that can inspect traffic more deeply and block more sophisticated attacks

NIPS (Network-based Intrusion Prevention System)

A type of IPS that monitors an entire network for suspicious traffic by analyzing protocol activity

The Simple Definition:

A security system that examines all network traffic for signs of attacks

NIST Framework

A set of guidelines for private sector organizations to follow to be prepared for and address cybersecurity risks

The Simple Definition:

A set of best practices from the U.S. government to help organizations manage cybersecurity risks

Network

A group of interconnected computers and peripherals that can communicate with each other

The Simple Definition:

A system of connected computers and devices that can share information

Network Security

The practice of protecting the usability and integrity of your network and data

The Simple Definition:

Protecting your computer networks from intruders and attacks

OSINT (Open Source Intelligence)

Data collected from publicly available sources to be used in an intelligence context

The Simple Definition:

Information gathered from public sources like social media and websites for security purposes

On-premises

Software and technology that is located within the physical confines of an organization rather than in the cloud

The Simple Definition:

IT systems that are physically located in your building rather than in the cloud