IT Acronyms and Flashcards

142 acronyms

AAAAuthentication, Authorization and Accounting

Proving who you are, deciding what you may do, and recording what you did. · Security

ACLAccess Control List

Ordered rules on a router, firewall or file that permit or deny access. · Security

AESAdvanced Encryption Standard

The standard symmetric block cipher, with 128-, 192- or 256-bit keys. · Security

APIPAAutomatic Private IP Addressing

Windows gives itself a 169.254.x.x address when it can’t reach DHCP. · Networking

APTAdvanced Persistent Threat

A skilled, well-funded attacker that stays hidden in a network for a long time. · Security

ARPAddress Resolution Protocol

Finds the MAC address for an IPv4 address on the local network. · Networking

AUPAcceptable Use Policy

Rules for how employees may use company systems. · Governance and risk

BCPBusiness Continuity Plan

How the business keeps running during and after a disruption. · Governance and risk

BGPBorder Gateway Protocol

The path-vector routing protocol that connects networks across the internet. · Networking

BIABusiness Impact Analysis

Identifies critical functions and what their loss would cost. · Governance and risk

BIOSBasic Input/Output System

Legacy firmware that starts the hardware and loads the operating system. · Hardware and OS

CACertificate Authority

A trusted party that issues and signs digital certificates. · Security

CASBCloud Access Security Broker

Sits between users and cloud services to enforce security policy. · Security

CDNContent Delivery Network

Servers around the world that cache content close to users. · Networking

CIDRClassless Inter-Domain Routing

Writes a network as address/prefix, like 10.0.0.0/8, instead of using classes. · Networking

CPUCentral Processing Unit

The processor that executes instructions. · Hardware and OS

CRLCertificate Revocation List

A CA’s list of certificates revoked before they expired. · Security

CSMA/CDCarrier-Sense Multiple Access with Collision Detection

How half-duplex Ethernet shares a medium and handles collisions. · Networking

CSRCertificate Signing Request

What you send a CA to get a certificate: your public key and identity details. · Security

CVECommon Vulnerabilities and Exposures

The public catalog of known vulnerabilities, each with an ID like CVE-2024-1234. · Security

CVSSCommon Vulnerability Scoring System

Scores a vulnerability’s severity from 0.0 to 10.0. · Security

DDoSDistributed Denial of Service

Flooding a target from many machines at once to knock it offline. · Security

DDRDouble Data Rate (memory)

RAM that transfers data twice per clock cycle; DDR4 and DDR5 today. · Hardware and OS

DHCPDynamic Host Configuration Protocol

Automatically assigns IP addresses, gateways and DNS servers. · Networking

DIMMDual Inline Memory Module

A desktop memory stick; laptops use the smaller SO-DIMM. · Hardware and OS

DLPData Loss Prevention

Tools that detect and stop sensitive data leaving the organization. · Security

DMZDemilitarized Zone

A screened subnet for public-facing servers, between the internet and the internal network. · Security

DNSDomain Name System

Translates names like example.com into IP addresses. · Networking

DNSSECDomain Name System Security Extensions

Signs DNS records so resolvers can verify they weren’t tampered with. · Networking

DRPDisaster Recovery Plan

How IT systems are restored after a disaster. · Governance and risk

EDREndpoint Detection and Response

Monitors endpoints for threats and lets you investigate and contain them. · Security

ESDElectrostatic Discharge

Static electricity that can destroy components; wear an anti-static strap. · Hardware and OS

FIMFile Integrity Monitoring

Alerts when important files change unexpectedly. · Security

FQDNFully Qualified Domain Name

A complete name including the host and every domain level, like www.example.com. · Networking

FTPFile Transfer Protocol

Transfers files on ports 20 and 21, in cleartext. · Networking

GDPRGeneral Data Protection Regulation

The EU’s data protection and privacy law. · Governance and risk

GPTGUID Partition Table

The modern partition scheme used with UEFI; it replaced MBR. · Hardware and OS

GPUGraphics Processing Unit

The processor for graphics and parallel workloads such as AI. · Hardware and OS

HDDHard Disk Drive

Storage on spinning magnetic platters. · Hardware and OS

HIDSHost-based Intrusion Detection System

Watches one host’s activity and logs for signs of attack. · Security

HIPAAHealth Insurance Portability and Accountability Act

US law protecting health information. · Governance and risk

HSMHardware Security Module

A tamper-resistant device that generates and stores cryptographic keys. · Security

HTTPHypertext Transfer Protocol

The protocol of the web, on port 80 (HTTPS on 443). · Networking

IaaSInfrastructure as a Service

Rent virtual machines, storage and networks; you manage the OS up. · Cloud and virtualization

IaCInfrastructure as Code

Defining infrastructure in files (Terraform, CloudFormation) so it’s repeatable. · Cloud and virtualization

IAMIdentity and Access Management

The policies and tools that manage identities and what they can access. · Security

ICMPInternet Control Message Protocol

Carries error and diagnostic messages; ping and traceroute use it. · Networking

IDSIntrusion Detection System

Detects and alerts on suspicious traffic or activity, without blocking it. · Security

IMAPInternet Message Access Protocol

Reads email kept on the server, synced across devices (port 143, 993 secure). · Networking

IoCIndicator of Compromise

Evidence an attack happened: a malicious IP, file hash or domain. · Security

IPSIntrusion Prevention System

Sits inline and blocks malicious traffic as well as detecting it. · Security

IPsecInternet Protocol Security

Authenticates and encrypts IP packets; the basis of many VPNs. · Networking

IPv6Internet Protocol version 6

The 128-bit successor to IPv4, written in hexadecimal. · Networking

ISPInternet Service Provider

The company that connects you to the internet. · Networking

KVMKeyboard, Video, Mouse (switch)

Controls several computers from one keyboard, monitor and mouse. · Hardware and OS

LANLocal Area Network

A network in one building or campus. · Networking

LDAPLightweight Directory Access Protocol

Queries and manages directory services like Active Directory (389, 636 secure). · Networking

MACMedia Access Control (address)

A network interface’s 48-bit hardware address. · Networking

MBRMaster Boot Record

The legacy partition scheme: up to four primary partitions and 2 TB disks. · Hardware and OS

MDMMobile Device Management

Enrolls and manages phones and tablets: policies, apps and remote wipe. · Hardware and OS

MFAMultifactor Authentication

Logging in with two or more factor types: something you know, have or are. · Security

MITMMan-in-the-Middle (on-path attack)

An attacker secretly relays and can alter traffic between two parties. · Security

MOUMemorandum of Understanding

A non-binding agreement setting out how two parties will work together. · Governance and risk

MPLSMultiprotocol Label Switching

Forwards traffic by labels instead of IP lookups, common in carrier WANs. · Networking

MTBFMean Time Between Failures

The average time a repairable system runs between failures. · Governance and risk

MTTRMean Time to Repair (Recover)

The average time it takes to fix a failure. · Governance and risk

MTUMaximum Transmission Unit

The largest packet a link carries without fragmenting; 1500 bytes on Ethernet. · Networking

NACNetwork Access Control

Checks a device’s identity and health before letting it on the network. · Security

NASNetwork-Attached Storage

A file server appliance on the network. · Hardware and OS

NATNetwork Address Translation

Rewrites private addresses to public ones as traffic leaves the network. · Networking

NDANon-Disclosure Agreement

A contract to keep information confidential. · Governance and risk

NGFWNext-Generation Firewall

A firewall that also inspects applications, users and content, often with IPS built in. · Security

NICNetwork Interface Card

The hardware that connects a device to a network. · Hardware and OS

NTFSNew Technology File System

Windows’ main file system, with permissions and encryption. · Hardware and OS

NTPNetwork Time Protocol

Synchronizes clocks over the network (UDP 123). · Networking

NVMeNon-Volatile Memory Express

A fast SSD interface over PCIe, often in an M.2 slot. · Hardware and OS

OCSPOnline Certificate Status Protocol

Checks a single certificate’s revocation status in real time. · Security

OSIOpen Systems Interconnection (model)

The seven-layer reference model, from Physical (1) to Application (7). · Networking

OSINTOpen-Source Intelligence

Information gathered from public sources such as websites and social media. · Security

OSPFOpen Shortest Path First

A link-state routing protocol used inside organizations. · Networking

PaaSPlatform as a Service

The provider runs the platform; you deploy your code and data. · Cloud and virtualization

PAMPrivileged Access Management

Controls, vaults and monitors administrator accounts and credentials. · Security

PATPort Address Translation

NAT that maps many private addresses to one public address using ports. · Networking

PCI DSSPayment Card Industry Data Security Standard

Security rules for anyone who stores or processes card payments. · Governance and risk

PCIePeripheral Component Interconnect Express

The expansion bus for graphics cards, NVMe drives and adapters. · Hardware and OS

PIIPersonally Identifiable Information

Data that can identify a person, such as name, ID number or address. · Governance and risk

PKIPublic Key Infrastructure

The CAs, certificates and policies that make public-key encryption trustworthy. · Security

PoEPower over Ethernet

Delivers power over the network cable to phones, cameras and access points. · Networking

POSTPower-On Self-Test

Firmware’s hardware check at startup, reported with beep codes or messages. · Hardware and OS

PSUPower Supply Unit

Converts wall power to the voltages the computer needs. · Hardware and OS

QoSQuality of Service

Prioritizes traffic such as voice and video over less urgent traffic. · Networking

RADIUSRemote Authentication Dial-In User Service

Central AAA for Wi-Fi, VPN and network logins (UDP 1812, 1813). · Networking

RAIDRedundant Array of Independent Disks

Combines drives for speed and/or redundancy: RAID 0, 1, 5, 10 and others. · Hardware and OS

RAMRandom Access Memory

Fast, volatile working memory. · Hardware and OS

RATRemote Access Trojan

Malware that gives an attacker remote control of a machine. · Security

RBACRole-Based Access Control

Permissions are given to roles, and users get them through their role. · Security

RDPRemote Desktop Protocol

Microsoft’s remote desktop protocol, on port 3389. · Hardware and OS

RPORecovery Point Objective

The most data loss you can accept, measured in time since the last backup. · Governance and risk

RSARivest–Shamir–Adleman

A widely used asymmetric algorithm for encryption and digital signatures. · Security

RTORecovery Time Objective

How quickly a system must be back after an outage. · Governance and risk

SaaSSoftware as a Service

Complete applications delivered over the internet, like Microsoft 365. · Cloud and virtualization

SAMLSecurity Assertion Markup Language

An XML standard for single sign-on between an identity provider and apps. · Security

SANStorage Area Network

A dedicated network that gives servers block-level storage. · Hardware and OS

SASESecure Access Service Edge

Networking and security (SD-WAN, SWG, CASB, ZTNA) delivered as one cloud service. · Security

SATASerial Advanced Technology Attachment

The common interface for internal hard drives and SSDs. · Hardware and OS

SD-WANSoftware-Defined Wide Area Network

Manages WAN links centrally and steers traffic across them by policy. · Networking

SDNSoftware-Defined Networking

Separates the network’s control plane from its data plane for central control. · Cloud and virtualization

SHASecure Hash Algorithm

A family of hash functions; SHA-256 is the common choice today. · Security

SIEMSecurity Information and Event Management

Collects and correlates logs from across the network to spot attacks. · Security

SLAService Level Agreement

A contract setting service levels such as uptime and response times. · Governance and risk

SMTPSimple Mail Transfer Protocol

Sends and relays email (port 25; 587 for submission). · Networking

SNMPSimple Network Management Protocol

Monitors and manages network devices (UDP 161, traps on 162). · Networking

SOARSecurity Orchestration, Automation and Response

Automates security responses with playbooks across tools. · Security

SOCSecurity Operations Center

The team that monitors, detects and responds to security incidents. · Security

SOPStandard Operating Procedure

Step-by-step instructions for a routine task. · Governance and risk

SSDSolid-State Drive

Storage on flash memory, with no moving parts. · Hardware and OS

SSIDService Set Identifier

The name of a wireless network. · Networking

SSOSingle Sign-On

One login gives access to many applications. · Security

STPSpanning Tree Protocol

Stops switching loops by blocking redundant paths. · Networking

TCPTransmission Control Protocol

Connection-oriented transport with a handshake, ordering and retransmission. · Networking

TLSTransport Layer Security

Encrypts data in transit; it replaced SSL and secures HTTPS. · Security

TOTPTime-based One-Time Password

A code that changes every 30 seconds, from an authenticator app. · Security

TPMTrusted Platform Module

A chip that stores keys securely and supports BitLocker and secure boot. · Security

TTLTime to Live

A hop counter that stops packets looping forever; also how long DNS records are cached. · Networking

UACUser Account Control

Windows prompts before an app makes changes that need administrator rights. · Hardware and OS

UDPUser Datagram Protocol

Connectionless transport: fast, with no delivery guarantee. · Networking

UEFIUnified Extensible Firmware Interface

Modern firmware replacing BIOS, with Secure Boot and GPT support. · Hardware and OS

UPSUninterruptible Power Supply

A battery that keeps equipment running through short power cuts. · Hardware and OS

USBUniversal Serial Bus

The standard port for peripherals; USB-C is the current connector. · Hardware and OS

UTMUnified Threat Management

One appliance combining firewall, IPS, antivirus and web filtering. · Security

VDIVirtual Desktop Infrastructure

Desktops that run on servers and stream to users’ devices. · Cloud and virtualization

VLANVirtual Local Area Network

Splits one switch into separate broadcast domains. · Networking

VMVirtual Machine

A software computer running on a hypervisor. · Cloud and virtualization

VoIPVoice over Internet Protocol

Phone calls carried over IP networks. · Networking

VPCVirtual Private Cloud

Your own isolated network inside a public cloud. · Cloud and virtualization

VPNVirtual Private Network

An encrypted tunnel across an untrusted network. · Networking

WAFWeb Application Firewall

Filters HTTP traffic to protect web apps from attacks like SQL injection and XSS. · Security

WANWide Area Network

A network spanning cities or countries, linking LANs. · Networking

WPA3Wi-Fi Protected Access 3

The current Wi-Fi security standard, with SAE replacing pre-shared key handshakes. · Networking

XDRExtended Detection and Response

Detection and response across endpoints, network, cloud and email together. · Security

XSSCross-Site Scripting

Injecting malicious scripts into web pages other users load. · Security

ZTNAZero Trust Network Access

Grants access to specific apps after verifying every request, never trusting by location. · Security