What is CI and CD?

CI/CD is a core practice in modern software development that automates the process of building, testing, and delivering code changes. CI stands for Continuous Integration, while CD stands for either Continuous Delivery or Continuous Deployment. Together, they form a pipeline that helps teams deliver software updates more frequently, with less risk and better quality.

Continuous Integration is the practice of frequently merging code changes into a shared repository, often multiple times per day. Each merge triggers an automated build and test process. The main goal is to detect integration issues early, ensuring that changes work together and don't break the existing codebase. When tests fail, developers get immediate feedback and can fix problems before they compound.

Continuous Delivery extends CI by ensuring that code is always in a deployable state. After the CI process passes, the code is automatically packaged and prepared for deployment to production. However, the actual deployment to production requires manual approval. This approach gives teams the flexibility to choose when to release, while maintaining confidence that the code is production-ready.

Continuous Deployment takes automation one step further by automatically deploying every change that passes the CI pipeline directly to production, without manual intervention. This requires robust testing and monitoring practices, as changes reach users immediately after passing automated checks. It's ideal for teams that need to release updates very frequently.