It is a nonrelational database i.e a NoSQL DB. It is a managed service, i.e you do not need to tune or manage it in any way, AWS does this for you.
It is a fast and flexible NoSQL DB for applications that need consistent single-digit milliseconds at any scale. It is a fully managed database and supports both document and key-value data models.
Amazon DynamoDB is a fully managed, serverless, key-value NoSQL database designed to run high-performance applications at any scale.
a single Dynamo DB table will be used to persist image details. All interactions with DynamoDB will happen via the Lambda functions.
What is DynamoDB?
Dynamo DB characteristics
DynamoDB pricing
DynamoDB data model
Simple DynamoDB architecture