Amazon AppSync supports multiple data sources, including the following AWS services:

Amazon DynamoDB: A fast and flexible NoSQL database service.

Amazon RDS: A managed relational database service for SQL, MySQL, PostgreSQL, and other databases.

AWS Lambda: A serverless computing platform that runs your code without requiring you to provision or manage servers.

Amazon S3: An object storage service that allows you to store, retrieve, and manage your data through the AWS Cloud.

HTTP Data Sources: You can also connect to any HTTP data source, including REST APIs and web services, using AppSync’s built-in support for HTTP resolvers.

These are the most commonly used data sources for AppSync. Other AWS services, like Amazon ElastiCache, Amazon Aurora, and Amazon Kinesis, can also be used as a data source for AppSync through custom Lambda resolvers.