CircleCI is a continuous integration and continuous delivery (CI/CD) platform that helps software development teams automate the process of building, testing, and deploying code. By streamlining these workflows, CircleCI enables teams to release software more quickly and reliably. It supports a wide range of programming languages and frameworks, and integrates seamlessly with major version control systems like GitHub, GitLab, and Bitbucket. CircleCI offers powerful features such as customizable pipelines, parallel builds, and comprehensive reporting tools, which help developers to achieve efficient software development practices.