Imagine you're building a complex model airplane. Every time you add a new piece, you have to manually check if the wings are still balanced, if the paint is dry, and if everything holds together. It's tedious and repetitive. Now, what if you had a robot that did all those checks for you automatically every single time you attached a new part? That's essentially what GitHub Actions does for your code.

In short, GitHub Actions is an automation tool built right into GitHub. Its job is to run a sequence of commands whenever a specific event happens in your repository. This could be anything from someone pushing new code to a new issue being created. These automated sequences are the heart of a modern development practice called Continuous Integration and Continuous Deployment, or CI/CD.

CI/CD is a method to deliver apps to customers frequently by introducing automation into the stages of app development. The main concepts attributed to CI/CD are continuous integration, continuous delivery, and continuous deployment.

• Continuous Integration (CI): This is the practice of developers merging their code changes into a central repository frequently. After each merge, an automated build and automated tests are run. The goal is to find and address bugs quicker, improve software quality, and reduce the time it takes to validate and release new software updates.

• Continuous Deployment (CD): This is the next step after integration. It automates the release of the successfully tested code to a production environment. This means that once your code passes all the automated tests, it can be live for users to see, without any human intervention.

GitHub Actions automates this entire pipeline. When a developer pushes code, an Action can automatically start the build process, run a suite of tests to check for errors, and if everything passes, deploy the new version of the application. This saves an enormous amount of time and prevents human error, ensuring that only high-quality, tested code reaches users.

The power of GitHub Actions goes beyond just CI/CD. You can automate almost any task related to your project. These automations are defined in files called workflows. A workflow is triggered by a specific event, like a code push or a pull request creation. The workflow then runs one or more jobs, which are sequences of steps. Each step can either be a shell command or an action, which is a reusable piece of code.

You could create workflows to:

• Welcome new contributors to your project.
• Automatically add labels to new issues and pull requests.
• Run code linters to check for style errors.
• Publish a package to a registry like npm or PyPI.
• Send a notification to a Slack channel when a deployment is complete.

Now that you have a high level understanding of what GitHub Actions is, let's test your knowledge.