CircleCI is a cloud-based continuous integration and continuous delivery (CI/CD) platform that helps developers automate the process of software development. It allows teams to build, test, and deploy their code quickly and efficiently, ensuring that new features and updates are delivered to users without delays. With CircleCI, developers can integrate their code repositories from platforms like GitHub and Bitbucket. The platform supports various programming languages and frameworks, enabling teams to customize their workflows. By automating repetitive tasks, CircleCI helps improve code quality and accelerates the development cycle.