What Is the Security+? Glossary & Key Terms

CIA Triad
The foundational security model comprising Confidentiality, Integrity, and Availability, used to evaluate and design protections for information systems.
Zero Trust
A security model that assumes no user or device is inherently trusted, requiring continuous verification of identity and context before granting access to resources, regardless of network location.
Attack Surface
The total sum of all points where an unauthorized user could attempt to enter or extract data from a system, including software, hardware, and human vectors.
Threat Actor
An individual or group responsible for carrying out a cyberattack, such as a nation-state, hacktivist, insider, or organized crime group, each with different motivations and capabilities.
Advanced Persistent Threat (APT)
A sophisticated, often state-sponsored threat actor that gains and maintains unauthorized, long-term access to a network to conduct stealthy, targeted operations such as espionage or data theft.
Botnet
A network of compromised, internet-connected devices controlled remotely by an attacker, commonly used to launch distributed denial-of-service attacks or spam campaigns.
Privilege Escalation
A technique in which an attacker gains higher-level access than originally granted, either vertically (obtaining admin rights) or horizontally (accessing other accounts at the same privilege level).
SQL Injection
An attack technique that inserts malicious SQL statements into input fields to manipulate a database, potentially exposing, altering, or deleting data.
Cross-Site Scripting (XSS)
A web application vulnerability where an attacker injects malicious scripts into trusted web pages, which then execute in the browsers of unsuspecting users.
Public Key Infrastructure (PKI)
The framework of policies, roles, hardware, and software used to create, manage, distribute, and revoke digital certificates that bind public keys to identities.
Certificate Authority (CA)
A trusted entity that issues and digitally signs digital certificates, vouching for the authenticity of the public key and identity contained within them.
Security Information and Event Management (SIEM)
A platform that aggregates, correlates, and analyzes log and event data from across an organization's systems in real time to detect and support response to security incidents.
Security Orchestration, Automation, and Response (SOAR)
A set of tools and processes that automate incident response workflows, integrating with security tools to execute predefined playbooks and reduce manual response time.
Data Loss Prevention (DLP)
A set of tools and policies designed to detect and prevent sensitive data from being exfiltrated, leaked, or improperly accessed outside authorized boundaries.
Role-Based Access Control (RBAC)
An access control model that assigns permissions to users based on their organizational role rather than individually, simplifying administration and enforcing least privilege.
Single Sign-On (SSO)
An authentication mechanism that allows a user to log in once and gain access to multiple independent systems or applications without re-authenticating for each.
Federation
A trust relationship between separate organizations or identity providers that allows users to authenticate once and access resources across multiple systems or domains.
Penetration Testing
An authorized, simulated cyberattack against a system performed to identify exploitable vulnerabilities before real attackers can find and use them.
Vulnerability Scanning
An automated process of identifying known security weaknesses in systems, applications, or networks by comparing them against databases of known vulnerabilities.
Incident Response Plan
A documented set of procedures for detecting, containing, eradicating, and recovering from security incidents, typically following phases such as preparation, identification, containment, eradication, recovery, and lessons learned.
Business Continuity Plan (BCP)
A documented strategy outlining how an organization will continue critical operations during and after a disruptive event.
Data Classification
The process of categorizing data based on its sensitivity and criticality (e.g., public, internal, confidential, restricted) to apply appropriate handling and protection controls.
Segmentation
The practice of dividing a network or system into isolated zones or subnets to limit the scope of a compromise and enforce controlled access between areas.
Threat Intelligence
Evidence-based knowledge about existing or emerging threats, including indicators of compromise and adversary tactics, used to inform proactive defensive decisions.