This tutorial demonstrates how to automatically create DynamoDB records from Cognito user signups in AWS Amplify applications. The video walks through setting up an Amplify app with authentication, creating a DynamoDB table for users, and implementing a Lambda trigger to add new users to the database upon signup. Key steps include configuring Amplify, creating a React frontend, setting up Cognito authentication, and writing a Lambda function to handle the user creation in DynamoDB. This approach allows developers to maintain user data in their own database while leveraging Cognito for authentication, enabling easier relationship management between users and other data models.