Continuous Integration (CI), Continuous Delivery (CD), and Continuous Deployment (CD) are practices that automate the process of getting code from development to production, each playing a unique role in the software development lifecycle. CI involves frequently integrating code changes into a shared repository with automated testing, while CD extends CI by automating the release process to a staging environment and retaining manual approval for final deployment. Continuous Deployment fully automates releases without any manual intervention. These practices improve productivity, reduce integration issues, and accelerate software delivery.