IT Acronym Decoder — 200+ Acronyms Explained

155 acronyms

Acronym	Full Name	Say it	Domain	What it means
API	Application Programming Interface	A-P-I	Dev	Interface that allows programs to communicate.
CI/CD	Continuous Integration / Continuous Deployment	C-I / C-D	DevOps	Automated build, test, and deploy pipeline.
MVP	Minimum Viable Product	M-V-P	Agile	Smallest product version that delivers value to users.
OKR	Objectives and Key Results	O-K-R	Agile	Goal-setting framework: objective + measurable outcomes.
KPI	Key Performance Indicator	K-P-I	Agile	Metric used to evaluate success against a goal.
SLA	Service Level Agreement	S-L-A	Agile	Contract defining expected uptime, support response times.
SLO	Service Level Objective	S-L-O	DevOps	Internal target for reliability (e.g. 99.9% uptime).
SLI	Service Level Indicator	S-L-I	DevOps	Metric measuring actual service level (e.g. latency, error rate).
MoSCoW	Must have / Should have / Could have / Won't have	MOS-co	Agile	Prioritisation technique for requirements.
DORA	DevOps Research and Assessment	DOR-a	DevOps	Four metrics: deployment frequency, lead time, MTTR, change failure rate.
MTTR	Mean Time To Recovery / Repair	M-T-T-R	DevOps	Average time to restore service after an incident.
MTTD	Mean Time To Detect	M-T-T-D	DevOps	Average time to detect an issue after it starts.
WIP	Work In Progress	WIP (rhymes with tip)	Agile	Unfinished tasks; Kanban boards limit WIP to improve flow.
PoC	Proof of Concept	P-o-C	Agile	Small experiment to validate that an idea is feasible.
RFC	Request for Comments	R-F-C	Dev	Document proposing a change; invites team/community feedback.
ADR	Architecture Decision Record	A-D-R	Dev	Document recording a significant architectural decision.
HTTP	HyperText Transfer Protocol	H-T-T-P	Networking	Foundation protocol for web data transfer.
HTTPS	HTTP Secure	H-T-T-P-S	Networking	HTTP encrypted with TLS.
REST	Representational State Transfer	REST (rhymes with best)	Networking	Architectural style for stateless HTTP APIs.
gRPC	Google Remote Procedure Call	G-R-P-C	Networking	High-performance RPC framework using Protocol Buffers.
DNS	Domain Name System	D-N-S	Networking	Translates domain names to IP addresses.
TCP	Transmission Control Protocol	T-C-P	Networking	Reliable, ordered, connection-oriented transport protocol.
UDP	User Datagram Protocol	U-D-P	Networking	Fast, connectionless transport protocol; no delivery guarantee.
SSL	Secure Sockets Layer	S-S-L	Security	Predecessor to TLS; often used informally to mean TLS.
TLS	Transport Layer Security	T-L-S	Security	Cryptographic protocol securing internet communications.
SSH	Secure Shell	S-S-H	Networking	Encrypted protocol for remote terminal access.
VPN	Virtual Private Network	V-P-N	Networking	Encrypted tunnel over a public network.
CDN	Content Delivery Network	C-D-N	Networking	Distributed servers delivering content from locations near users.
NAT	Network Address Translation	NAT (rhymes with cat)	Networking	Remaps IP addresses as packets pass through a router.
IP	Internet Protocol	I-P	Networking	Addressing protocol for routing packets across networks.
OSI	Open Systems Interconnection (model)	O-S-I	Networking	7-layer model describing network communication layers.
IaaS	Infrastructure as a Service	I-A-A-S	Cloud	Cloud model: you manage OS and up; provider manages hardware.
PaaS	Platform as a Service	PAAS (rhymes with "mass")	Cloud	Cloud model: provider manages runtime; you deploy apps.
SaaS	Software as a Service	SAAS (rhymes with "mass")	Cloud	Cloud model: provider delivers full application (e.g. Gmail).
IaC	Infrastructure as Code	I-A-C	Cloud	Managing infrastructure via configuration files (Terraform, etc.).
VPC	Virtual Private Cloud	V-P-C	Cloud	Isolated virtual network within a cloud provider.
IAM	Identity and Access Management	I-A-M	Cloud	Framework for managing who can do what in cloud resources.
S3	Simple Storage Service	S-3	Cloud	AWS object storage service.
EC2	Elastic Compute Cloud	E-C-2	Cloud	AWS virtual machine service.
ECS	Elastic Container Service	E-C-S	Cloud	AWS managed container orchestration.
EKS	Elastic Kubernetes Service	E-K-S	Cloud	AWS managed Kubernetes.
GKE	Google Kubernetes Engine	G-K-E	Cloud	GCP managed Kubernetes.
AKS	Azure Kubernetes Service	A-K-S	Cloud	Azure managed Kubernetes.
HA	High Availability	H-A	Cloud	System design ensuring minimal downtime through redundancy.
DR	Disaster Recovery	D-R	Cloud	Plan and systems for recovering from catastrophic failures.
RPO	Recovery Point Objective	R-P-O	Cloud	Maximum acceptable data loss measured in time.
RTO	Recovery Time Objective	R-T-O	Cloud	Maximum acceptable downtime before service recovery.
CVE	Common Vulnerabilities and Exposures	C-V-E	Security	Standard identifier for publicly known security vulnerabilities.
OWASP	Open Web Application Security Project	OH-wasp	Security	Non-profit producing web security standards (OWASP Top 10).
XSS	Cross-Site Scripting	X-S-S	Security	Injection of malicious scripts into trusted web pages.
CSRF	Cross-Site Request Forgery	C-S-R-F	Security	Attack tricking users into executing unwanted actions.
SQLi	SQL Injection	S-Q-L injection	Security	Attack injecting malicious SQL into database queries.
MFA	Multi-Factor Authentication	M-F-A	Security	Authentication requiring two or more verification factors.
2FA	Two-Factor Authentication	2-F-A	Security	A specific type of MFA using exactly two factors.
SSO	Single Sign-On	S-S-O	Security	Authentication allowing one login across multiple systems.
RBAC	Role-Based Access Control	R-BAC	Security	Permissions assigned to roles, not individual users.
ABAC	Attribute-Based Access Control	A-BAC	Security	Access decisions based on attributes (user, resource, environment).
PII	Personally Identifiable Information	P-I-I	Security	Data that can identify a specific individual (name, email, SSN).
GDPR	General Data Protection Regulation	G-D-P-R	Security	EU regulation governing personal data collection and processing.
SOC2	System and Organization Controls 2	SOC 2	Security	Security audit framework for SaaS companies.
SIEM	Security Information and Event Management	SIM (like "seem")	Security	Real-time security event aggregation, analysis, and alerting.
JWT	JSON Web Token	JOT or J-W-T	Security	Compact token format for securely transmitting claims.
OAuth	Open Authorization	OH-auth	Security	Authorization framework allowing limited third-party access.
OIDC	OpenID Connect	O-I-D-C	Security	Authentication layer built on top of OAuth 2.0.
ETL	Extract, Transform, Load	E-T-L	Data	Data pipeline pattern: extract from source, transform, load to target.
ELT	Extract, Load, Transform	E-L-T	Data	Modern variant: load raw data first, transform in the warehouse.
ML	Machine Learning	M-L	Data	AI subset where models learn from data.
LLM	Large Language Model	L-L-M	Data	Neural network trained on large text corpora (GPT, Claude, LLaMA).
NLP	Natural Language Processing	N-L-P	Data	ML field focused on understanding and generating human language.
RAG	Retrieval-Augmented Generation	RAG (rhymes with bag)	Data	LLM technique combining retrieval of documents with generation.
GPU	Graphics Processing Unit	G-P-U	Data	Parallel processor; used for ML training and rendering.
TPU	Tensor Processing Unit	T-P-U	Data	Google custom chip optimised for neural network computation.
OLAP	Online Analytical Processing	OH-lap	Data	Database approach optimised for complex analytical queries.
OLTP	Online Transaction Processing	O-L-T-P	Data	Database approach optimised for fast transactional reads/writes.
DWH	Data Warehouse	D-W-H	Data	Central repository of integrated data from multiple sources.
DAG	Directed Acyclic Graph	DAG (rhymes with bag)	Data	Data structure used in workflow orchestration (Airflow, etc.).
SQL	Structured Query Language	sequel OR S-Q-L	Database	Language for querying relational databases.
ORM	Object-Relational Mapper	O-R-M	Database	Library mapping database rows to in-memory objects.
ACID	Atomicity, Consistency, Isolation, Durability	ACID (like the word)	Database	Four properties guaranteeing reliable database transactions.
CAP	Consistency, Availability, Partition tolerance	CAP (like the word)	Database	Theorem: distributed systems can only guarantee 2 of 3.
CRUD	Create, Read, Update, Delete	CRUD (rhymes with "food")	Database	Four basic operations of persistent storage.
DDL	Data Definition Language	D-D-L	Database	SQL subset for defining schema (CREATE, ALTER, DROP).
DML	Data Manipulation Language	D-M-L	Database	SQL subset for data operations (INSERT, UPDATE, DELETE).
DRY	Don't Repeat Yourself	DRY (like the word)	Dev	Principle: avoid code duplication; extract repeated logic.
SOLID	Single responsibility, Open-closed, Liskov, Interface segregation, Dependency inversion	SOLID (like the word)	Dev	5 object-oriented design principles.
YAGNI	You Aren't Gonna Need It	YAG-nee	Dev	Principle: don't add functionality until it's needed.
KISS	Keep It Simple, Stupid	KISS (like the word)	Dev	Principle: favour simplicity over unnecessary complexity.
TDD	Test-Driven Development	T-D-D	Dev	Write tests first, then write code to pass them.
BDD	Behaviour-Driven Development	B-D-D	Dev	TDD variant using human-readable Given/When/Then scenarios.
DDD	Domain-Driven Design	D-D-D	Dev	Software design centered on the business domain and its language.
CQRS	Command Query Responsibility Segregation	C-Q-R-S	Dev	Pattern separating read and write operations.
IoC	Inversion of Control	I-O-C	Dev	Design principle: framework calls your code, not the other way.
DI	Dependency Injection	D-I	Dev	Technique providing dependencies from outside rather than creating them.
MVC	Model-View-Controller	M-V-C	Dev	Architectural pattern separating concerns into 3 layers.
DTO	Data Transfer Object	D-T-O	Dev	Object carrying data between processes; no business logic.
OOP	Object-Oriented Programming	O-O-P	Dev	Paradigm based on objects with data and methods.
FP	Functional Programming	F-P	Dev	Paradigm treating computation as evaluation of pure functions.
DOM	Document Object Model	DOM (rhymes with "mom")	Frontend	Tree representation of an HTML/XML document.
SSR	Server-Side Rendering	S-S-R	Frontend	HTML generated on the server before sending to browser.
SSG	Static Site Generation	S-S-G	Frontend	HTML generated at build time, served as static files.
CSR	Client-Side Rendering	C-S-R	Frontend	HTML generated in the browser using JavaScript.
PWA	Progressive Web Application	P-W-A	Frontend	Web app with native app features (offline, install prompt, push).
SPA	Single-Page Application	S-P-A	Frontend	Web app loading once and updating dynamically without page reloads.
ARIA	Accessible Rich Internet Applications	AR-ee-a	Frontend	HTML attributes improving accessibility for assistive technologies.
WCAG	Web Content Accessibility Guidelines	WE-cag	Frontend	W3C guidelines for making web content accessible.
BEM	Block Element Modifier	BEM (like the word)	Frontend	CSS naming convention: Block__Element--Modifier.
LCP	Largest Contentful Paint	L-C-P	Frontend	Core Web Vital: time to render the largest visible element.
CLS	Cumulative Layout Shift	C-L-S	Frontend	Core Web Vital: measure of unexpected layout shifts.
INP	Interaction to Next Paint	I-N-P	Frontend	Core Web Vital: responsiveness of a page to user interactions.
PR	Pull Request	P-R	Dev	Request to merge a branch; triggers code review.
MR	Merge Request	M-R	Dev	GitLab term for what GitHub calls a Pull Request.
LGTM	Looks Good To Me	L-G-T-M	Dev	Code review abbreviation meaning approval.
WIP	Work In Progress	WIP (rhymes with tip)	Dev	Draft PR prefix indicating it is not ready for review.
ETA	Estimated Time of Arrival / Estimated Time of Action	E-T-A	Workplace	"What is the ETA on that feature?" — when will it be ready.
EOD	End of Day	E-O-D	Workplace	"Please send the report by EOD." Usually means 5–6 PM local time.
EOW	End of Week	E-O-W	Workplace	Deadline shorthand meaning by Friday close of business.
OOO	Out of Office	O-O-O	Workplace	Email auto-reply status or Slack indication.
TBD	To Be Determined	T-B-D	Workplace	Placeholder for something not yet decided.
TBD	To Be Discussed	T-B-D	Workplace	Alternative meaning in meeting agenda context.
TL;DR	Too Long; Didn't Read	T-L-D-R	Workplace	Summary section at top of a long document; also: "short version".
FYI	For Your Information	F-Y-I	Workplace	Sharing information without requiring action.
ASAP	As Soon As Possible	AY-sap or A-S-A-P	Workplace	Urgency indicator; use with caution in professional writing.
QA	Quality Assurance	Q-A	Workplace	Process of testing and validating software before release.
PM	Product Manager / Project Manager	P-M	Workplace	Depends on context: product strategy (Product PM) vs delivery planning (Project PM).
PO	Product Owner	P-O	Agile	Scrum role: owns the product backlog and prioritisation.
SM	Scrum Master	S-M	Agile	Facilitates Scrum ceremonies; removes team impediments.
EM	Engineering Manager	E-M	Workplace	Manager responsible for engineers' career growth and team delivery.
IC	Individual Contributor	I-C	Workplace	A non-manager role; engineers, designers, writers etc.
DAU	Daily Active Users	D-A-U	Metrics	Number of unique users who engage with a product in a day.
MAU	Monthly Active Users	M-A-U	Metrics	Number of unique users who engage in a 30-day period.
MRR	Monthly Recurring Revenue	M-R-R	Metrics	Predictable revenue generated per month from subscriptions.
ARR	Annual Recurring Revenue	A-R-R	Metrics	Yearly version of MRR.
LTV	Lifetime Value (of a customer)	L-T-V	Metrics	Predicted total revenue a customer generates over their lifetime.
CAC	Customer Acquisition Cost	C-A-C	Metrics	Total cost to acquire one new customer.
NPS	Net Promoter Score	N-P-S	Metrics	−100 to +100 measure of customer loyalty and satisfaction.
ARPU	Average Revenue Per User	AR-pu	Metrics	MRR divided by total active users.
p99	99th percentile (latency)	P-ninety-nine	Metrics	99% of requests complete faster than this value.
YAML	YAML Ain't Markup Language	YAM-ul	Dev	Human-readable data serialisation format for config files.
JSON	JavaScript Object Notation	JAY-sun	Dev	Lightweight data interchange format; used in APIs and configs.
XML	eXtensible Markup Language	X-M-L	Dev	Verbose markup/data format; largely replaced by JSON in APIs.
SDK	Software Development Kit	S-D-K	Dev	Collection of tools, libraries, and docs for building on a platform.
IDE	Integrated Development Environment	I-D-E	Dev	Code editor with built-in compiler, debugger, and tools (VS Code, IntelliJ).
VM	Virtual Machine	V-M	Cloud	Software emulation of a physical computer.
OS	Operating System	O-S	Dev	Software managing hardware and providing services to programs.
CLI	Command-Line Interface	C-L-I	Dev	Text-based interface for interacting with a computer.
GUI	Graphical User Interface	GOO-ee	Frontend	Visual interface with windows, buttons, and icons.
UI	User Interface	U-I	Frontend	Everything a user can see and interact with in a product.
UX	User Experience	U-X	Frontend	How a user feels when interacting with a product.
FOSS	Free and Open Source Software	FOSS (rhymes with "boss")	Dev	Software that is free to use and open for modification.
OSS	Open Source Software	O-S-S	Dev	Software with publicly available source code.
QPS	Queries Per Second	Q-P-S	Metrics	Measure of throughput for databases and search engines.
RPS	Requests Per Second	R-P-S	Metrics	Measure of throughput for APIs and web servers.
EOF	End of File	E-O-F	Dev	Marker indicating end of a data stream or file.
OOM	Out of Memory	O-O-M	Dev	Error when a process exceeds available memory.
GC	Garbage Collection	G-C	Dev	Automatic memory management reclaiming unused allocations.