AWS AppSync is a fully managed service that makes it easy to create and manage GraphQL and Real-time APIs, allowing developers to securely access, manipulate, and combine data from one or more data sources via a single API endpoint. With GraphQL, special functions called Resolvers are used to implement business logic linking or “resolving” types, fields, or operations defined in the GraphQL schema with the data in data sources such as Amazon DynamoDB, AWS Lambda, HTTP APIs, and more.
Source:: Amazon AWS