What Is CI/CD?
Continuous Integration, Delivery and Deployment
CI/CD is a set of practices that automate how code changes are tested, built and released. The abbreviation covers related ideas: continuous integration (CI) and continuous delivery or continuous deployment (both CD).
- Continuous integration: developers merge their changes into a shared branch often, and each change automatically triggers a build and a set of tests.
- Continuous delivery: every change that passes the tests is kept in a releasable state, so release becomes a decision rather than a major task.
- Continuous deployment: every change that passes the pipeline is released to production automatically, without a manual approval step.
How a Deployment Pipeline Works
A pipeline is the automated sequence of steps that runs when code changes. A typical pipeline fetches the code from the Git repository, installs dependencies, runs automated tests, checks code quality, builds the application and deploys it to a staging environment. A later stage may deploy to production, sometimes after a person approves the change.
If any stage fails, the pipeline stops and the team is notified, so a broken change never reaches visitors. Pipelines are usually defined in a configuration file stored with the code and run on the platform that hosts the repository or on a dedicated build server.
Benefits and Trade-offs
The main benefit is fewer manual errors. Deployments that follow the same steps every time are easier to repeat and to undo. Teams also get faster feedback, because problems surface minutes after a change is made rather than weeks later.
The trade-offs are setup effort and maintenance. Tests must be written and kept current, and a pipeline needs deployment credentials that must be protected. A poorly maintained test suite can give false confidence.
Frequently asked questions
Is CI/CD Only for Large Development Teams?
No. Solo developers and small teams use CI/CD to run tests automatically and to make deployments repeatable. The practice scales down easily: a single pipeline with a test step and one deployment target may be enough for a small website or application.
What Is the Difference Between Continuous Delivery and Continuous Deployment?
The difference is the final step. With continuous delivery, a tested change is ready to release, but someone decides when to deploy it. With continuous deployment, every change that passes the pipeline goes live automatically. Both rely on the same automated testing and build process.
Does CI/CD Replace Manual Testing?
Not entirely. Automated tests check what they were written to check, and they catch regressions quickly. Exploratory testing, usability review and checks on real devices still need people. CI/CD makes the automated part reliable and frequent.