A
Acceptance Testing
A formal testing phase where end users verify that a system or software meets requirements before it is approved for release.
Access Control
The process of restricting access to systems, networks, and data to authorised users only, based on defined roles and permissions.
AD
Active Directory. A Microsoft directory service that manages users, computers, and resources on a Windows network using centralised authentication.
API
Application Programming Interface. A set of protocols and tools that allow software applications to communicate and share data with each other.
Asset Management
The practice of tracking and managing an organisation's IT hardware, software, and infrastructure throughout their entire lifecycle.
B
BIOS
Basic Input/Output System. Firmware stored on a chip that initialises hardware during startup and provides runtime services for the operating system.
Business Continuity
A set of processes and plans that ensure critical business operations can continue during and after a major disruption or disaster.
Business Impact Analysis
A process that identifies how a disruption to IT services would affect business operations, used to prioritise recovery efforts.
BYOD
Bring Your Own Device. A policy that permits employees to use personal devices such as laptops, tablets, and smartphones for work purposes.
C
Capacity Planning
The process of forecasting future IT resource needs to ensure infrastructure can meet anticipated demand without over-provisioning.
CDN
Content Delivery Network. A distributed network of servers that delivers web content from the geographically closest node to reduce latency.
Change Management
A structured process for reviewing, approving, and implementing changes to IT systems to minimise risk and disruption.
CLI
Command Line Interface. A text-based interface for interacting with software or an OS by typing commands instead of using a graphical interface.
Cloud Computing
The delivery of computing services such as storage, processing, and software over the internet on a pay-as-you-use basis.
CMDB
Configuration Management Database. A repository that stores information about IT assets, their configurations, and relationships used in ITSM processes.
Cold Standby
A backup system kept offline that must be manually started and configured before it can take over from a failed primary system.
CPU
Central Processing Unit. The primary processor of a computer that executes instructions and performs calculations for the operating system and applications.
D
Data Center
A dedicated facility housing servers, storage, and networking equipment that stores and processes an organisation's data.
Data Migration
The process of moving data from one system, format, or storage location to another, typically during upgrades or system consolidations.
DDoS
Distributed Denial of Service. A cyberattack where multiple compromised systems flood a target with traffic to overwhelm and take it offline.
DHCP
Dynamic Host Configuration Protocol. A network protocol that automatically assigns IP addresses and network settings to devices when they connect.
Disaster Recovery
A set of policies and procedures to restore IT systems and data following a major failure, cyberattack, or natural disaster.
DNS
Domain Name System. A naming system that translates human-readable domain names into IP addresses, allowing browsers to locate web servers.
E
End of Life
The point at which a vendor ceases to provide updates, patches, or support for a product, increasing security and stability risks.
End User
The person who ultimately uses a system, application, or device; the primary recipient of IT support and services.
ERP
Enterprise Resource Planning. Integrated software that manages and automates core business processes such as finance, HR, and supply chain.
Escalation
The process of transferring a support ticket to a higher tier or more specialised team when first-line support cannot resolve the issue.
F
Failover
The automatic switching to a backup system or component when the primary one fails, minimising downtime and service disruption.
FCR
First Call Resolution. A key helpdesk metric measuring the percentage of support requests resolved during the customer's initial contact, without follow-up.
FTP
File Transfer Protocol. A standard network protocol used to transfer files between a client and a server over a TCP/IP network.
G
GPU
Graphics Processing Unit. A specialised processor designed to accelerate rendering of graphics, also widely used for parallel computing tasks.
GUI
Graphical User Interface. A visual interface that lets users interact with software using graphical elements like windows, icons, and menus.
H
Help Desk
A centralised team or function that provides technical support and assistance to users experiencing IT issues or service requests.
Hot Standby
A backup system running in parallel with the primary, ready to take over immediately if the primary fails with no manual intervention.
HTTP
Hypertext Transfer Protocol. The foundation of data communication on the web, defining how messages are formatted and transmitted between browsers and servers.
HTTPS
Hypertext Transfer Protocol Secure. An encrypted version of HTTP that uses TLS to secure data in transit between a browser and a web server.
I
IaaS
Infrastructure as a Service. A cloud model that provides virtualised computing resources such as servers, storage, and networking on demand.
IAM
Identity and Access Management. A framework of policies and technologies that ensures only authorised users can access specific IT resources.
Incident
An unplanned interruption or reduction in quality of an IT service, logged as a ticket and managed through the incident management process.
Incident Response
An organised approach to managing the aftermath of a security breach or IT incident to limit damage and reduce recovery time.
IP
Internet Protocol. The principal communications protocol used to relay data across network boundaries, identified by a numeric address.
ISP
Internet Service Provider. A company that provides individuals and businesses with access to the internet and related network services.
IT Governance
A framework of policies, processes, and accountability structures that align IT activities with business goals and regulatory requirements.
ITIL
Information Technology Infrastructure Library. A framework of best practices for delivering IT services aligned with business needs and customer expectations.
ITSM
IT Service Management. A set of policies and practices for managing IT services to meet business needs, commonly following the ITIL framework.
K
Knowledge Base
A self-service repository of articles, guides, and FAQs that users can search to resolve issues without contacting support.
KPI
Key Performance Indicator. A measurable value used to evaluate how effectively an organisation or service is achieving its objectives.
L
LAN
Local Area Network. A network that connects computers and devices within a limited area such as an office building or single campus.
Least Privilege
A security principle that restricts user and system accounts to only the minimum permissions needed to perform their required tasks.
Load Balancing
The distribution of incoming network traffic across multiple servers to ensure no single server is overwhelmed, improving reliability.
M
MAC
Media Access Control. A unique hardware identifier assigned to a network interface card for communication on a physical network segment.
MFA
Multi-Factor Authentication. A security process requiring users to verify identity using two or more independent credentials before access is granted.
MTTR
Mean Time to Resolution. The average time taken to fully resolve a support incident from the moment it is logged to the moment it is closed.
N
NAT
Network Address Translation. A method that remaps IP address spaces, typically allowing multiple devices to share a single public IP address.
Network Segmentation
The practice of dividing a network into smaller, isolated segments to limit the spread of threats and improve security control.
Network Topology
The physical or logical arrangement of nodes and connections in a network, such as star, ring, mesh, or bus configurations.
NIC
Network Interface Card. A hardware component that connects a computer to a network, enabling wired or wireless communication.
O
OS
Operating System. System software that manages computer hardware and software resources and provides common services for programs.
OTP
One-Time Password. A temporary password valid for only one login session or transaction, used to strengthen authentication security.
P
PaaS
Platform as a Service. A cloud model that provides a managed environment for developers to build, run, and deploy applications without managing infrastructure.
Patch Management
The process of regularly applying software updates and security patches to systems to fix vulnerabilities and improve stability.
Priority
A classification assigned to a ticket based on urgency and impact, used to determine the order in which incidents are addressed by the support team.
Problem Management
An ITSM process focused on identifying and eliminating the root causes of recurring incidents to prevent future occurrences.
Project Management
The application of processes, skills, and methods to plan, execute, and close projects within defined scope, time, and budget.
R
RAID
Redundant Array of Independent Disks. A data storage technology that combines multiple drives to provide redundancy, improved performance, or both.
RAM
Random Access Memory. Volatile memory that temporarily stores data and instructions currently in use by the CPU for fast access.
RDP
Remote Desktop Protocol. A Microsoft protocol that allows users to remotely connect to and control another computer over a network.
Remote Desktop
Technology allowing a support agent to view and control a user's computer screen over a network to diagnose and resolve issues without being on-site.
ROM
Read-Only Memory. Non-volatile memory that permanently stores firmware or data and retains its contents even when the power is off.
Root Cause Analysis
A structured method used to identify the underlying cause of a problem or incident rather than treating only its symptoms.
S
SaaS
Software as a Service. A cloud delivery model in which software is hosted remotely and accessed by users via a web browser on subscription.
Scope Creep
The gradual, uncontrolled expansion of a project's requirements or deliverables beyond its originally agreed scope without formal approval.
SDK
Software Development Kit. A collection of tools, libraries, and documentation that developers use to build applications for a specific platform.
Service Catalog
A directory of IT services available to users, describing each offering, eligibility, delivery times, and how to request them.
Service Delivery
The process of providing agreed IT services to users and the business in a consistent, reliable, and measurable manner.
Service Desk
The single point of contact between IT and users, handling incidents, service requests, and communication throughout their lifecycle.
Single Point of Failure
A component whose failure would cause the entire system to stop functioning, representing a critical reliability and availability risk.
SLA
Service Level Agreement. A formal agreement between a service provider and a customer that defines expected service standards, response times, and resolution targets.
SMTP
Simple Mail Transfer Protocol. The standard protocol used to send emails between mail servers and from email clients to mail servers.
Software License
A legal agreement granting permission to use software under defined terms, including the number of users, duration, and permitted uses.
SSH
Secure Shell. A cryptographic protocol that provides a secure channel for remote login and command execution over unsecured networks.
SSL
Secure Sockets Layer. A cryptographic protocol that established encrypted links between servers and clients; largely superseded by TLS.
SSO
Single Sign-On. An authentication method that allows users to access multiple applications with one set of login credentials.
System Administrator
An IT professional responsible for configuring, maintaining, and securing servers, networks, and other systems infrastructure.
T
TCP
Transmission Control Protocol. A connection-oriented protocol that ensures reliable, ordered delivery of data between applications over a network.
Technical Debt
The accumulated cost of shortcuts, quick fixes, or outdated code that must eventually be addressed through rework or refactoring.
Threat Vector
A path or method used by an attacker to gain unauthorised access to a network, system, or data.
Ticket
A formal record in a helpdesk system that tracks a user's reported issue or request from initial submission through to resolution and closure.
TLS
Transport Layer Security. A cryptographic protocol that provides secure communications over a network, replacing the older SSL standard.
TPM
Trusted Platform Module. A hardware chip that stores cryptographic keys and provides hardware-based security for encryption and authentication.
U
UDP
User Datagram Protocol. A connectionless protocol that sends data without establishing a connection, prioritising speed over reliability.
URL
Uniform Resource Locator. The address used to access a resource on the internet, specifying protocol, domain, path, and optional parameters.
USB
Universal Serial Bus. A standard interface for connecting peripheral devices such as keyboards, mice, and storage drives to a computer.
User Story
A short, plain-language description of a feature written from the end user's perspective to guide development and delivery priorities.
V
VM
Virtual Machine. An emulation of a computer system that runs on a host machine, sharing its physical resources while operating independently.
VoIP
Voice over Internet Protocol. Technology that transmits voice communications over the internet instead of traditional telephone lines.
VPN
Virtual Private Networking - a means of securely accessing resources on a network by connecting to a remote access server through the Internet or other network.
W
WAN
Wide Area Network. A network that spans a large geographical area, connecting multiple LANs across cities, countries, or globally.
Workaround
A temporary solution that restores service to a user while the underlying root cause of an incident is still being investigated or resolved.
WSUS
Windows Server Update Services. A Microsoft server role that manages distribution of updates and patches to Windows computers on a network.
Z
Zero Trust
A security model that requires continuous verification of every user and device, assuming no implicit trust even within the network perimeter.