instruction: Show github_actions configuration examples with best practices
output: Understanding GitHub Actions
  Learn the basics of core concepts and essential terminology in GitHub Actions.
  In this article
  Overview
  
  GitHub Actions is a continuous integration and continuous delivery (CI/CD) platform that allows you to automate your build, test, and deployment pipeline. You can create workflows that build and test every pull request to your repository, or deploy merged pull requests to production.
  
  GitHub Actions goes beyond just DevOps and lets you run workflows when other events happen in your repository. For example, you can run a workflow to automatically add the appropriate labels whenever someone creates a new issue in your repository.
  
  GitHub provides Linux, Windows, and macOS virtual machines to run your workflows, or you can host your own self-hosted runners in your own data center or cloud infrastructure.
  
  The components of GitHub Actions
  
  You can configure a GitHub Actions 
  workflow
   to be triggered when an 
  event
   occurs in your repository, such as a pull request being opened or an issue being created. Your workflow contains one or more 
  jobs
   which can run in sequential order or in parallel. Each job will run inside its own virtual machine 
  runner
  , or inside a container, and has one or more 
  steps
   that either run a script that you define or run an 
  action
  , which is a reusable extension that can simplify your workflow.
  
  Workflows
  
  A 
  workflow
   is a configurable automated process that will run one or more jobs. Workflows are defined by a YAML file checked in to your repository and will run when triggered by an event in your repository, or they can be triggered manually, or at a defined schedule.
  
  Workflows are defined in the 
  .github/workflows
   directory in a repository. A repository can have multiple workflows, each of which can perform a different set of tasks such as:
  
  Building and testing pull requests
  
  Deploying your application every time a release is created
  
  Adding a label whenever a new issue is opened
  
  You can reference a workflow within another workflow. For more information, see 
  Reuse workflows
  .
  
  For more information, see 
  Writing workflows
  .
  
  Events
  
  An 
  event
   is a specific activity in a repository that triggers a 
  workflow
   run. For example, an activity can originate from GitHub when someone creates a pull request, opens an issue, or pushes a commit to a repository. You can also trigger a workflow to run on a 
  schedule
  , by 
  posting to a REST API
  , or manually.
  
  For a complete list of events that can be used to trigger workflows, see 
  Events that trigger workflows
  .
  
  Jobs
  
  A 
  job
   is a set of 
  steps
   in a workflow that is executed on the same 
  runner
  . Each step is either a shell script that will be executed, or an 
  action
   that will be run. Steps are executed in order and are dependent on each other. Since each step is executed on the same runner, you can share data from one step to another. For example, you can have a step that builds your application followed by a step that tests the application that was built.
  
  You can configure a job's dependencies with other jobs; by default, jobs have no dependencies and run in parallel. When a job takes a dependency on another job, it waits for the dependent job to complete before running.
  
  You can also use a 
  matrix
   to run the same job multiple times, each with a different combination of variables—like operating systems or language versions.
  
  For example, you might configure multiple build jobs for different architectures without any job dependencies and a packaging job that depends on those builds. The build jobs run in parallel, and once they complete successfully, the packaging job runs.
  
  For more information, see 
  Choosing what your workflow does
  .
  
  Actions
  
  An 
  action
   is a pre-defined, reusable set of jobs or code that performs specific tasks within a 
  workflow
  , reducing the amount of repetitive code you write in your workflow files. Actions can perform tasks such as:
  
  Pulling your Git repository from GitHub
  
  Setting up the correct toolchain for your build environment
  
  Setting up authentication to your cloud provider
  
  You can write your own actions, or you can find actions to use in your workflows in the GitHub Marketplace.
  
  For more information on actions, see 
  Reusing automations
  .
  
  Runners
  
  A 
  runner
   is a server that runs your workflows when they're triggered. Each runner can run a single 
  job
   at a time.
  GitHub provides Ubuntu Linux, Microsoft Windows, and macOS runners to run your 
  workflows
  . Each workflow run executes in a fresh, newly-provisioned virtual machine.
  
  GitHub also offers larger runners, which are available in larger configurations. For more information, see 
  Using larger runners
  .
  
  If you need a different operating system or require a specific hardware configuration, you can host your own runners.
  
  For more information about self-hosted runners, see 
  Managing self-hosted runners
  .
  
  Next steps
  
  GitHub Actions can help you automate nearly every aspect of your application development processes. Ready to get started? Here are some helpful resources for taking your next steps with GitHub Actions:
  
  To create a GitHub Actions workflow, see 
  Using workflow templates
  .
  
  For continuous integration (CI) workflows, see 
  Building and testing your code
  .
  
  For building and publishing packages, see 
  Publishing packages
  .
  
  For deploying projects, see 
  Deploying to third-party platforms
  .
  
  For automating tasks and processes on GitHub, see 
  Managing your work with GitHub Actions
  .
  
  For examples that demonstrate more complex features of GitHub Actions, see 
  Managing your work with GitHub Actions
  . These detailed examples explain how to test your code on a runner, access the GitHub CLI, and use advanced features such as concurrency and test matrices.
  
  To certify your proficiency in automating workflows and accelerating development with GitHub Actions, earn a GitHub Actions certificate with GitHub Certifications. For more information, see 
  About GitHub Certifications
  .