DevOps glossary

This DevOps glossary defines, in one sentence, the key terms you will meet in our courses: containers, orchestration, infrastructure as code, automation and pipelines. Each definition is self-contained and links, where relevant, to the related course.

DevOps

DevOps is a culture and a set of practices that bring development (Dev) and operations (Ops) closer together to deliver software faster, more often and more reliably.

CI/CD

CI/CD (continuous integration / continuous delivery) automates building, testing and deploying code, to ship changes quickly and safely. See our DevOps CI/CD course.

Pipeline

A pipeline is a sequence of automated steps (build, tests, deployment) triggered on every code change.

Container

A container is an isolated software unit bundling an application and its dependencies, lighter than a virtual machine because it shares the host’s kernel.

Docker

Docker is the most widely used containerisation tool: it packages an application into a portable image that runs identically everywhere. See our Docker course.

Image (container)

An image is a read-only template containing an application and its environment; it is instantiated to create containers.

Kubernetes (K8s)

Kubernetes is an open-source orchestrator that automatically deploys, scales and manages containers across a cluster of machines. See our Kubernetes course.

Orchestration

Orchestration automates the deployment, scaling, availability and networking of large numbers of containers.

Cluster

A cluster is a set of machines (nodes) working together; Kubernetes distributes and manages containers across it.

Pod

A pod is the smallest deployable unit in Kubernetes: one or more containers sharing network and storage.

Helm

Helm is the Kubernetes package manager: it packages and deploys applications through reusable ‘charts’.

Infrastructure as Code (IaC)

Infrastructure as Code means describing and provisioning your infrastructure (servers, networks…) through versioned files rather than manually.

Terraform

Terraform is an Infrastructure as Code tool that provisions cloud resources declaratively and reproducibly. See our Terraform course.

Ansible

Ansible is an agentless automation tool for configuring servers and deploying applications from YAML files. See our Ansible course.

Provisioning

Provisioning is the automatic setup of the resources (machines, services) an application needs.

GitOps

GitOps is an approach where the desired state of infrastructure and deployments is described in Git — a single source of truth — and applied automatically.

Registry (image registry)

An image registry is a repository that stores and distributes container images (Docker Hub, GitHub/GitLab Container Registry…).

Microservices

A microservices architecture splits an application into small independent services, deployed and scaled separately.

Observability

Observability covers the means (logs, metrics, traces) of understanding the state and behaviour of a system in production.

Blue-green / canary deployment

Progressive deployment strategies: blue-green switches between two identical environments, canary exposes the new version to a fraction of users before full rollout.

Rollback

A rollback is the quick return to a previous, stable version when a problem occurs after a deployment.