# Introduction to prefabs

> Understand what prefabs are and when to use them.

You can use prefabs to reuse [GameObject](/engine/6000.7/manual/working-with-gameobjects/game-objects.md) configurations in multiple places in a scene or across different scenes in your project. The prefab system keeps all copies of a GameObject in sync, so when you make changes to a prefab asset, Unity updates all instances of that prefab automatically. This allows you to update multiple GameObjects without needing to edit each copy individually.


**A selection of prefabs in the Project window.:**
![](/api/media?file=/engine/6000.7/media/images/prefabs-overview.png)

Common uses for prefabs include:

* **Environmental assets:** For example, a specific type of tree used multiple times in a level.
* **Non-player characters (NPCs):** For example, a robot that appears in multiple levels, with differences (using overrides) such as movement speed or sound.
* **Projectiles:** For example, a pirate ship's cannon instantiates a cannonball prefab each time it's fired.
* **Main playable character:** The character prefab can be placed at the starting point in each scene of your game.

Prefabs are also useful when you want to [instantiate GameObjects at runtime](/engine/6000.7/manual/working-with-gameobjects/prefabs/instantiating.md) that don't exist in your scene at the start. For example, you might spawn in-game items, special effects, projectiles, or NPCs during gameplay.

## Working with prefabs

To work with prefabs, you [create a prefab asset](/engine/6000.7/manual/working-with-gameobjects/prefabs/creating.md), which you then use to create prefab instances within a scene.

You can [nest prefabs](/engine/6000.7/manual/working-with-gameobjects/prefabs/nested.md) inside other prefabs to create complex hierarchies of objects that you can edit at multiple levels. However, not all prefab instances need to be identical. You can [override](/engine/6000.7/manual/working-with-gameobjects/prefabs/override/prefab-instance-overrides.md) settings on individual prefab instances if you want some to differ from others. You can also create [prefab variants](/engine/6000.7/manual/working-with-gameobjects/prefabs/prefab-variants.md) to group a set of overrides into different variations of a prefab.

If you override prefabs it's useful to understand the difference between the prefab's source, and its original source, so you can determine what parts of a prefab are overridden:

* **Source**: The nearest prefab asset in the inheritence chain that defines the object.
* **Original source**: The root prefab asset that originally introduced the object.

For example, if you create a prefab asset named `Light` and used it in a scene, the corresponding sources are as follows:

| **Prefab type**                                                                             | **Source**                       | **Original source**              |
| ------------------------------------------------------------------------------------------- | -------------------------------- | -------------------------------- |
| [Prefab instance](/engine/6000.7/manual/working-with-gameobjects/prefabs/creating.md)       | Original `Light` prefab asset.   | Original `Light` prefab asset.   |
| [Prefab variant](/engine/6000.7/manual/working-with-gameobjects/prefabs/prefab-variants.md) | Variant of `Light` prefab asset. | Original `Light` prefab asset.   |
| [Nested prefab](/engine/6000.7/manual/working-with-gameobjects/prefabs/nested.md)           | The nested `Light` prefab asset. | The nested `Light` prefab asset. |

You can use the [`PrefabUtility.GetCorrespondingObjectFromSource`](/engine/6000.7/script-reference/unityeditor/prefabutility/getcorrespondingobjectfromsource.md) method to get the source of a prefab, and [`GetCorrespondingObjectFromOriginalSource`](/engine/6000.7/script-reference/unityeditor/prefabutility/getcorrespondingobjectfromoriginalsource.md) to get the original source of the prefab.

## Prefab Inspector previews

When you select a prefab, its Inspector window contains an Asset Preview pane which displays a preview of the prefab. If the prefab is smaller than 8 MB, the preview is interactive, and you can rotate the prefab in the pane.

If the prefab is larger than 8 MB, the Asset Preview displays a static image by default. To view an interactive preview for larger prefabs, click anywhere inside the Asset Preview pane.

## Additional resources

* [Creating prefabs](/engine/6000.7/manual/working-with-gameobjects/prefabs/creating.md)
* [The Inspector window](/engine/6000.7/manual/unity-editor/editor-windows-views-reference/using-the-inspector.md)