GitHub Actions Mastery

GitHub Actions is GitHub's native CI/CD (continuous integration/continuous deployment) automation platform. Workflows are YAML-defined pipelines that run tests, linting, builds, and deployments automatically when code is pushed or PR is created. Workflows trigger on events: push, pull request, schedule (cron), webhook. Key components: (1) workflows (YAML files in .github/workflows/), (2) jobs (parallel or sequential units of work), (3) steps (individual commands or actions), (4) secrets (encrypted credentials), (5) artifacts (build outputs). Actions leverage reusable components (actions) from GitHub Marketplace.