Amazon DocumentDB is a fully managed NoSQL database service by AWS, designed to be compatible with MongoDB workloads, offering flexible and scalable data storage and management capabilities, including schema-less or schema-flexible document formats, scalability through horizontal scaling, collections for grouping documents, and indexing for efficient querying. It's a document database that stores data in JSON-like documents, providing seamless integration with CData connectivity solutions, allowing developers to quickly build applications using BI, reporting, and ETL tools, with minimal changes required from MongoDB applications.