Amazon DocumentDB is a fully managed database service designed to work with MongoDB applications. It allows users to store, query, and manage JSON-like documents, making it easy to handle semi-structured data. With built-in scalability and high availability, it can automatically adjust to varying workloads. The service is compatible with existing MongoDB drivers and tools, enabling developers to migrate their applications with minimal changes. Amazon DocumentDB also provides features like automated backups, encryption, and monitoring, ensuring that data is secure and easily accessible while reducing the operational overhead for users.