What it does
GitHub Actions is the automation system attached to GitHub repositories. A workflow is a YAML file in `.github/workflows`; triggers such as a push start jobs, and steps run on a selected runner. Teams use it to build, test, package or deploy code. The workflow definition belongs in the repository, while the Actions interface shows runs and results.
A small first workflow can respond to push and run a command on an Ubuntu runner. GitHub's quickstart places a .yml or .yaml file under .github/workflows, then defines a workflow name, trigger, job, runner and steps. A realistic next step is replacing the sample commands with a build and test command for the project. The workflow is configuration in version control, so the same change review can cover both application code and its automation.
Jobs run on GitHub-hosted runners or self-hosted runners. Hosted runners reduce machine maintenance; self-hosted runners give the repository owner more control and shift machine upkeep to that team. Secrets, artifact retention and runner selection matter once a workflow handles deployments or private build inputs.
Billing depends on repository visibility and account plan. Standard GitHub-hosted runners are free for public repositories, while private repositories receive plan-dependent allowances and additional usage is billed. Self-hosted runner usage is free under the documented policy, but the team still operates the machines.
Strengths
- Workflow files are versioned with the repository and can run on pushes or other events.
- Jobs can use GitHub-hosted runners or self-hosted runners.
- The same workflow can combine build, test, and deployment steps.
Watch out for
- Private repository usage can exceed included minutes or storage and become billable.
- Self-hosted runners transfer machine maintenance to the repository owner.
Best for
- Running build and test jobs for a repository on each push
- Automating releases or deployment from reviewed workflow files
Sources
- Quickstart for GitHub Actions (Oct 25, 2026)
- GitHub Actions billing - GitHub Docs (Oct 25, 2026)