DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. It offers key-value and document data models, consistent and low-latency performance, continuous availability and automatic scaling of storage and throughput capacity. The document discusses DynamoDB's data model, operations, indexing capabilities and use cases like building a game scores and leaderboards application. It also shares a customer story of how market research firm IBOPE was able to develop a scalable system to monitor websites and collect advertising data using AWS services like DynamoDB for its flexibility and ability to quickly scale resources up and down as needed.