GitHub Actions enable you to create custom software development lifecycle workflows directly in your GitHub repository https://help.github.com/en/articles/about-github-actions
Workflows are custom automated processes that you can set up in your repository to build, test, package, release, or deploy https://help.github.com/en/articles/about-github-actions
Workflow file The YAML file that defines your workflow configuration. This file lives in .github/workflows https://help.github.com/en/articles/about-github-actions