Unions are used when we want a GraphQL field or list to handle multiple types of data. With a Union Type, we can define a field that could resolve completely different types of data. In this lesson, we will write a query that obtains a list of different pet types

 

 

Unit type, we cannot use common field in query, I have to write in fragment:

# Write your query or mutation herequery {  familyPets {    __typename,    ... on Cat {      name    },    ... on Dog {      name    }  }}