GitHub Actions

GitHub Actions is GitHub's built-in CI/CD platform. It allows you to automate workflows directly from your repository — building, testing, and deploying code in response to events like pushes, pull requests, and releases.

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Why GitHub Actions?

• Integrated — lives inside your GitHub repository, no external service to configure
• Free for public repos — unlimited minutes for open-source projects
• Marketplace — thousands of pre-built actions for common tasks
• Matrix builds — test across multiple OS/language versions easily
• Secrets management — built-in encrypted secret storage
• Self-hosted runners — run on your own infrastructure if needed

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Core Concepts

Concept	Description
Workflow	A YAML file in .github/workflows/ that defines automation
Event	A trigger that starts a workflow (push, PR, schedule, manual)
Job	A set of steps that run on a single runner
Step	An individual task — either a shell command or an action
Action	A reusable unit of code (from Marketplace or custom)
Runner	The machine (VM) that executes a job

Hierarchy