Confusion with GraphQL Tools / Schema Merging

[nguyenyou]

As the documentation of GraphQL Tools said: Originally implemented in graphql-modules.

My question is: "What is the difference between graphql-modules and graphql-tools/schema-merge?

[dotansimha]

graphql-modules is implementing schema-merging concept, with added developer tools (like dependency injection, simple lifecycle based on GraphQL, and the concept of modules separation and validation), and it depends on graphql-tools.