Amazon DynamoDB is a fully managed NoSQL database service provided by Amazon Web Services (AWS). It allows users to store and retrieve any amount of data, serving high-traffic applications with low latency. DynamoDB automatically scales to handle large volumes of requests and offers built-in security features. DynamoDB uses a key-value and document data model, making it flexible for various applications. It supports features like automatic backups, in-memory caching with DynamoDB Accelerator (DAX), and global tables for multi-region replication. This makes it suitable for applications that require high availability and performance.