| title: Unions | |
| intro: A union is a type of object representing many objects. | |
| redirect_from: | |
| - /v4/union | |
| - /v4/reference/union | |
| versions: | |
| fpt: '*' | |
| ghec: '*' | |
| ghes: '*' | |
| topics: | |
| - API | |
| autogenerated: graphql | |
| ## About unions | |
| A [union](https://spec.graphql.org/June2018/#sec-Unions) is a type of object representing many objects. | |
| For example, a field marked as an [`ProjectCardItem`](/graphql/reference/unions#projectcarditem) could be an [`Issue`](/graphql/reference/objects#issue) or a [`PullRequest`](/graphql/reference/objects#pullrequest) because each of those objects can be inside a project card. Using a union instead of an object gives you flexibility. | |
| For more information, see [AUTOTITLE](/graphql/guides/introduction-to-graphql). | |
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