Data in DynamoDB is stored in tables. A table contains items (similar to rows), and each item contains attributes, (similar to columns). Each item can have a different set of attributes and the same attribute names may be used with different types in different items. 

DynamoDB supports the datatypes string, number, binary, Boolean, string set, number set, binary set, and list. 

DynamoDB does not have a JSON data type; however, you can pass JSON data to DynamoDB using the SDK and it will be mapped to native DynamoDB data types.

You can also define indexes (global secondary indexes and local secondary indexes) to improve read performance.