AppSync is a service from AWS that lets you configure a GraphQL API over your AWS data sources including DynamoDB, Lambda, and Elasticsearch. It seems to be aimed at getting a backend up and running quickly and with minimal fuss.
Their UI is easy to navigate. I was able to create a schema, connect it to Dynamo and query items pretty quickly.
They offer features that help you build your schema. For example, you can “import” from a DynamoDB table and in the process, the appropriate Graphql types are generated for you.
You can also create a resource from a type and they will spin up a DynamoDB table behind the scenes.
Specifying Lambdas a resolvers gives you access to whatever datasource you want, whether in AWS or otherwise.
Having experience building schemas by hand, helped me get going, I think it may be a bit much for someone new to GraphQL.