DevOps Terminology Glossary
A plain-English reference for common DevOps and software infrastructure terminology.
Jump to: A · B · C · D · E · F · G · H · I · J · K · L · M · N · O · P · Q · R · S · T · U · V · W · X · Y · Z
A
ACL — Access Control List; rules defining which users or systems may access a resource.
Agent — Software that performs work or reports information on behalf of another system.
Agile — An iterative approach to delivering software in small increments.
Alert — A notification triggered when a monitored condition is met.
Ansible — An automation tool for configuring machines and deploying applications.
API — Application Programming Interface; a defined way for programs to communicate.
API Gateway — A service that routes, secures, and manages API requests.
Artifact — A build output such as a binary, package, or container image.
Artifact Registry — A repository for storing and distributing build artifacts.
Authentication — Verifying the identity of a user or system.
Authorization — Determining what an authenticated identity may do.
Autoscaling — Automatically changing computing capacity in response to demand.
Availability — The proportion of time a service is usable.
B
Backoff — Increasing the wait between repeated attempts after failures.
Backup — A copy of data kept for recovery.
Bare Metal — A physical server without a virtualization layer between the OS and hardware.
Bash — A common Unix shell and scripting language.
Bastion Host — A hardened entry point for administrative access to private systems.
Blue-Green Deployment — A release strategy that switches traffic between two environments.
Branch — An independent line of development in version control.
Build — The process of turning source code into a deployable output.
Build Agent — A worker that executes build or pipeline jobs.
Build Cache — Previously computed build outputs reused to speed later builds.
Burn Rate — How quickly a service consumes its error budget.
C
Cache — Stored data reused to avoid repeating expensive work.
Canary Deployment — A rollout that first exposes a change to a small group.
CD — Continuous Delivery or Continuous Deployment, depending on context.
Certificate — A signed digital document used to establish identity or trust.
CI — Continuous Integration; frequently merging and automatically testing changes.
CI/CD — Automated processes for building, testing, and delivering software.
CLI — Command-Line Interface; a text-based way to operate software.
Cloud Computing — On-demand computing resources provided as services.
Cloud Native — Designing applications to use cloud-oriented deployment and scaling patterns.
Cluster — A group of computers working together.
CMDB — Configuration Management Database; an inventory of IT assets and relationships.
Commit — A recorded change in version control.
Configuration Drift — Differences between a system's actual and intended configuration.
Configuration Management — Keeping system settings consistent and controlled.
Container — An isolated process environment packaged with application dependencies.
Container Image — A packaged filesystem and metadata used to start containers.
Container Registry — A service for storing and distributing container images.
Continuous Delivery — Keeping software ready for release through automated validation.
Continuous Deployment — Automatically releasing validated changes to production.
Cron — A Unix scheduler for recurring commands.
CRUD — Create, Read, Update, Delete; four basic data operations.
CSI — Container Storage Interface; a standard for storage integration with orchestrators.
D
Daemon — A background service process, especially on Unix-like systems.
Dashboard — A visual summary of metrics and system status.
Database Migration — A controlled change to a database schema or data.
Declarative Configuration — Describing the desired end state rather than each action to reach it.
Dependency — Software or infrastructure required by another component.
Deployment — Releasing and running a version of software in an environment.
DevSecOps — Integrating security practices throughout development and operations.
DNS — Domain Name System; translates domain names into DNS records such as IP addresses.
Docker — A platform and tooling ecosystem for building and running containers.
Dockerfile — Instructions for building a Docker-compatible container image.
Downtime — A period when a service is unavailable.
DR — Disaster Recovery; restoring operations after a serious disruption.
Drift Detection — Identifying differences between desired and actual infrastructure state.
E
Edge Computing — Processing data closer to where it is generated or consumed.
Encryption — Transforming data so unauthorized parties cannot read it.
Endpoint — An address or interface where a service can be accessed.
Environment — A deployment context such as development, staging, or production.
Environment Variable — A named value passed into a process's runtime environment.
Error Budget — The allowed amount of unreliability under a service-level objective.
ETL — Extract, Transform, Load; a process for moving and preparing data.
Event-Driven Architecture — A design in which components react to emitted events.
F
Failover — Switching to a backup component after a failure.
Feature Flag — A switch used to enable or disable behavior without redeploying.
Firewall — A system that filters network traffic according to rules.
Fork — A separate copy of a repository used for independent development.
FQDN — Fully Qualified Domain Name; a complete name in the DNS hierarchy.
FTP — File Transfer Protocol; an older protocol for transferring files.
G
Garbage Collection — Automatic removal of unused memory or resources.
Git — A distributed version control system.
GitOps — Managing infrastructure or deployments through version-controlled desired state.
Golden Image — A preconfigured system or machine image used as a deployment baseline.
Grafana — A platform for dashboards, visualization, and observability.
Greenfield — A project built without needing to preserve an existing implementation.
H
HA — High Availability; designing systems to minimize service interruption.
Health Check — A test used to determine whether a component is functioning.
Helm — A package manager for Kubernetes applications.
Horizontal Scaling — Adding more instances to increase capacity.
Host — A computer or environment that runs workloads or services.
HTTP — Hypertext Transfer Protocol; a protocol for web requests and responses.
HTTPS — HTTP protected with TLS encryption.
Hypervisor — Software or firmware that runs virtual machines.
I
IaC — Infrastructure as Code; managing infrastructure using machine-readable definitions.
IAM — Identity and Access Management; identities, roles, and access policies.
Idempotency — A property where repeating an operation has the same intended effect as doing it once.
Immutable Infrastructure — Replacing deployed systems instead of modifying them in place.
Incident — An unplanned event that disrupts or threatens a service.
Infrastructure — The computing, networking, storage, and services supporting applications.
Ingress — Incoming network traffic; in Kubernetes, also an API for HTTP routing rules.
Integration Test — A test of how multiple components work together.
IP Address — A numerical address used to identify a network interface.
ISO Image — A disk image format commonly used to distribute operating systems.
J
Jenkins — An automation server commonly used for CI/CD pipelines.
Job — A unit of work scheduled or executed by an automation system.
JSON — JavaScript Object Notation; a widely used structured data format.
JWT — JSON Web Token; a compact format for signed or encrypted claims.
K
K8s — A common abbreviation for Kubernetes.
Kernel — The core operating-system component managing hardware and processes.
Key Pair — Related public and private cryptographic keys.
Kubernetes — A platform for orchestrating containerized workloads.
Kustomize — A tool for customizing Kubernetes YAML configurations.
L
Latency — The delay before a request or operation completes.
Least Privilege — Granting only the access needed to perform a task.
Linux — A family of operating systems built around the Linux kernel.
Load Balancer — A component that distributes traffic among multiple backends.
Log — A timestamped record of an event or activity.
Log Aggregation — Collecting logs from multiple sources into one system.
LTS — Long-Term Support; a release maintained for an extended period.
M
Manifest — A file declaring application, package, or infrastructure metadata.
Merge — Combining changes from different version-control branches.
Metric — A numeric measurement of system behavior.
Microservice — A small, independently deployable service within a larger system.
Middleware — Software that processes requests between application components.
MTTD — Mean Time to Detect; average time to discover an issue.
MTTR — Mean Time to Recovery or Repair; average time to restore service.
Multi-Tenancy — An architecture in which multiple customers share a service with isolation.
N
Namespace — A logical scope for organizing and isolating named resources.
NAT — Network Address Translation; rewriting network addresses in packets.
Network Policy — Rules controlling permitted network communication.
Nginx — A web server commonly used as a reverse proxy and load balancer.
Node — A machine participating in a cluster.
NTP — Network Time Protocol; synchronizes clocks over networks.
O
OAuth 2.0 — A framework for delegated authorization.
Observability — Understanding internal system behavior through telemetry and analysis.
On-Call — A rotation assigning responsibility for responding to incidents.
OpenTelemetry — A framework and standards for generating and exporting telemetry.
Orchestration — Coordinating automated tasks or workloads across systems.
OSI Model — A seven-layer conceptual model of network communication.
P
Package Manager — A tool for installing and updating software packages.
Patch — A change that fixes a defect or security issue.
Pipeline — An automated sequence of build, test, or deployment stages.
Pod — The smallest deployable workload unit in Kubernetes, containing one or more containers.
Podman — A daemonless container engine for managing OCI containers.
Postmortem — A review of an incident, its causes, and follow-up improvements.
Prometheus — A monitoring system and time-series metrics database.
Provisioning — Creating and configuring computing resources.
Proxy — An intermediary that forwards requests or traffic.
Pull Request — A proposal to review and merge code changes.
Q
Quality Gate — A check that must pass before work moves to the next stage.
Queue — A buffer of work items waiting to be processed.
Quota — A limit on the amount of resources that may be used.
R
RBAC — Role-Based Access Control; permissions assigned through roles.
RCA — Root Cause Analysis; investigating the underlying contributors to a problem.
Recovery Point Objective (RPO) — The maximum acceptable amount of data loss measured in time.
Recovery Time Objective (RTO) — The target maximum time to restore a service after disruption.
Registry — A service storing named artifacts, packages, or container images.
Replica — An additional copy of a service instance or dataset.
Repository — A storage location for source code, packages, or artifacts.
REST — Representational State Transfer; an architectural style for networked APIs.
Retry — Attempting an operation again after failure.
Reverse Proxy — A server that receives client requests and forwards them to backend services.
Rollback — Returning a deployment or change to an earlier state.
Rolling Deployment — Replacing application instances gradually while keeping service available.
Runner — A worker that executes CI/CD jobs.
S
SaaS — Software as a Service; applications delivered over a network.
SBOM — Software Bill of Materials; an inventory of software components and dependencies.
Secret — Sensitive data such as credentials, tokens, or private keys.
Secret Management — Secure storage, distribution, and rotation of sensitive values.
Semantic Versioning — A versioning convention using MAJOR.MINOR.PATCH numbers.
Serverless — A model where the platform manages server provisioning and scaling.
Service Discovery — Finding service instances and their network locations dynamically.
Service Mesh — Infrastructure for managing service-to-service communication.
SFTP — SSH File Transfer Protocol; secure file transfer over SSH.
Shift Left — Moving testing, security, or validation earlier in development.
SLA — Service Level Agreement; a commitment about service performance or availability.
SLI — Service Level Indicator; a measurement of service reliability.
SLO — Service Level Objective; a target value for an SLI.
Snapshot — A point-in-time representation of data or system state.
SRE — Site Reliability Engineering; applying engineering practices to service reliability.
SSH — Secure Shell; encrypted remote login and command execution.
SSL — Secure Sockets Layer; an obsolete predecessor of TLS.
Staging — A preproduction environment used for final validation.
Stateful Application — An application that preserves data or session state across operations.
Stateless Application — An application that does not depend on locally retained session state.
Subnet — A logical subdivision of an IP network.
Supply Chain Security — Protecting software dependencies, build systems, and distribution paths.
T
Tag — A label identifying a specific version or resource.
Technical Debt — Future maintenance cost caused by expedient design or implementation choices.
Telemetry — Collected signals such as logs, metrics, and traces.
Terraform — A tool for provisioning infrastructure through declarative configuration.
Throughput — The amount of work completed per unit of time.
TLS — Transport Layer Security; a protocol for protecting network connections.
Trace — A record of how a request travels through components.
Trunk-Based Development — A workflow using frequent small integrations into a shared main branch.
TTL — Time to Live; a lifetime or expiration value for data or packets.
U
Unit Test — A test of a small, isolated piece of code.
Uptime — The amount of time a system remains operational.
URI — Uniform Resource Identifier; a string identifying a resource.
URL — Uniform Resource Locator; a URI that locates a resource.
UTC — Coordinated Universal Time; a common reference for timestamps.
V
Vault — A system for securely storing and controlling access to secrets.
Version Control — Tracking and managing changes to files over time.
Vertical Scaling — Increasing the resources of an existing machine or instance.
Virtual Machine (VM) — A software-defined computer running its own operating system.
VLAN — Virtual Local Area Network; logical segmentation of a network.
Volume — Persistent or managed storage mounted into a workload.
VPN — Virtual Private Network; an encrypted connection across another network.
Vulnerability — A weakness that could be exploited to compromise a system.
W
WAF — Web Application Firewall; filters HTTP traffic to protect web applications.
Webhook — An HTTP request sent automatically when a specified event occurs.
Worker — A process or machine that performs background or assigned tasks.
Workflow — A defined sequence of steps to complete a process.
Workload — An application or set of tasks consuming computing resources.
X
X.509 — A standard format for public-key certificates.
XML — Extensible Markup Language; a structured text data format.
XSS — Cross-Site Scripting; injection of malicious scripts into web content.
Y
YAGNI — You Aren't Gonna Need It; a principle against building unneeded features.
YAML — A human-readable data serialization format used in configuration files.
Z
Zero Downtime Deployment — A release that avoids user-visible service interruption.
Zero Trust — A security model requiring explicit verification rather than implicit network trust.
Zombie Process — A terminated Unix process whose parent has not yet collected its exit status.