CircleCI offers a platform for continuous integration and continuous delivery (CI/CD) that automates the testing and deployment of code for engineering teams. The platform can be used in the cloud or on-premises, allowing clients to choose the best deployment model for their needs. CircleCI operates on a subscription basis, providing a free tier to attract new users, and aims to reduce the time and effort required for software development. The company's goal is to help teams release high-quality software faster and with more confidence.