CI (Continuous Integration)
It Automatically integrate and validate code changes. Developers frequently merge code into a shared repository.Each change triggers an automated build and automated tests (unit, integration, etc.).Helps detect bugs early and ensures that the new code doesn’t break existing functionality.

Example: A developer pushes a new feature to GitHub. The CI pipeline runs tests via tools like GitHub Actions, Jenkins, or Azure DevOps.

CD (Continuous Delivery)
It Automatically prepare code for release to production.Builds on top of CI.Ensures that code is deployable at any time, but deployment is still manual.Includes steps like staging environment deployment, functional tests, and approvals.

Example: After CI passes, the system pushes the app to a staging server. A human decides when to push it to production.

Continuous Deployment
It Automatically deploy every change that passes CI/CD to production — no manual intervention.Extends Continuous Delivery with fully automated production releases.Requires robust testing and monitoring — there’s no human gatekeeping.Ideal for organizations practicing DevOps or releasing frequently.

Example: Every code commit that passes all tests gets deployed to the live production environment automatically.