To assist in on-boarding new users. (#2385)

* To assist in on-boarding new users.

* Update data.md

docs/source/essentials/data.md

@@ -44,6 +44,8 @@ const resolvers = {
 };
 ```
 
+With the resolver map above, the query, `{ author { books } }`, will call the `Query.author` resolver first and pass its result to `Author.books`. The query result will contain the return value of `Author.books` nested under `data.author.books`.
+
 Note that you don't have to put all of your resolvers in one object. Refer to the ["modularizing the schema"](/docs/graphql-tools/generate-schema.html#modularizing) section to learn how to combine multiple resolver maps into one.
 
 <h2 id="type-signature">Resolver type signature</h2>