Skip to main content
Explore the core components of GitHub Actions and how they fit together. This guide clarifies workflows, jobs, steps, and actions with a compact example and a quick reference table to help you design CI/CD automation in your repository.

​
Core concepts

GitHub Actions consists of three primary building blocks:
  • Workflows — define when and how automation runs.
  • Jobs — independent units of work within a workflow that execute on a runner.
  • Steps — sequential tasks inside a job that call actions or run commands.

​
Workflow

A workflow is an automated process defined in a YAML file stored in your repository under .github/workflows. A repository may contain multiple workflows. Each workflow runs in response to one or more events (triggers) and can include an optional name that appears in the Actions tab.
Workflow definition files live in the .github/workflows directory of your repository.

​
Jobs

Jobs are the units inside a workflow. A workflow can contain one or more jobs. Each job runs on a runner (GitHub-hosted or self-hosted). Specify the runner using the runs-on attribute (for example, runs-on: ubuntu-latest).

​
Steps

Steps are the atomic operations within a job. Steps execute sequentially on the job’s runner. A step can:
  • Use an action via uses: (reusable component).
  • Run shell commands with run:.

​
Example workflow

This example illustrates a workflow with a job that runs unit tests on push events. 
name: My Awesome App
on: push
jobs:
  unit-testing:
    name: Unit Testing
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Install NodeJS
        uses: actions/setup-node@v3
        with:
          node-version: 20

      - name: Install Dependencies
        run: npm install

      - name: Run Unit Tests
        run: npm test
Explanation of the example:
  • on: push — triggers the workflow for push events.
  • unit-testing — job identifier; name: Unit Testing is the display name.
  • runs-on: ubuntu-latest — uses a GitHub-hosted Ubuntu runner.
  • Steps (executed in order):
    • Checkout: actions/checkout@v3 fetches the repository.
    • Install NodeJS: actions/setup-node@v3 configures Node.js (node-version: 20).
    • Install Dependencies: runs npm install.
    • Run Unit Tests: runs npm test.

​
Quick reference table

ComponentPurposeExample
WorkflowDefines the automation and triggerson: push
JobA group of steps that runs on a runnerruns-on: ubuntu-latest
StepA single task in a job (runs sequentially)run: npm test or uses: actions/checkout@v3
ActionReusable automation component used by stepsuses: actions/setup-node@v3

​
Actions (reusable components)

Actions are modular, reusable components that simplify automation tasks. You can author your own actions or consume community and official ones from GitHub Marketplace. Common use cases for actions:
  • Building and pushing Docker images to registries.
  • Provisioning or managing cloud resources (e.g., Azure AKS).
  • Fetching secrets from HashiCorp Vault using hashicorp/vault-action.
Examples:
  • Build and push Docker images: action that builds an image and pushes to Docker Hub or a container registry.
  • Azure integrations: actions for creating and managing Azure Kubernetes Service resources.
  • Secrets management: hashicorp/vault-action for injecting secrets as environment variables.
A slide titled "GitHub Actions" showing three numbered workflow steps. The steps are: 1) Build and push Docker images, 2) Create AKS Cluster, and 3) Consume Vault Secrets, each with corresponding Docker/Azure/Vault icons.
Triggers/events, runners, and advanced action patterns (composite actions, JavaScript and Docker actions, permissions) are covered in more detail elsewhere.

Watch Video