# Code reload and serialization

> Understand when Unity reloads compiled code, and how it preserves the state of objects across a reload.

Understand when Unity reloads compiled code, and how it preserves the state of objects across a reload.

When you change a script, the Unity Editor reloads compiled code and rebuilds the state of the objects. Unity writes object states to a serialized form and restores it afterward. The same serialization rules determine which fields appear in the Inspector window and which values persist in assets and scenes.

| **Topic**                                                                                                                   | **Description**                                                                                                                                                                           |
| --------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **[Code reload](/engine/6000.7/manual/programming-environment/code-reload-serialization/code-reload.md)**                   | Understand when the Unity Editor reloads code, and configure what Unity reloads when you enter Play mode.                                                                                 |
| **[Script serialization](/engine/6000.7/manual/programming-environment/code-reload-serialization/script-serialization.md)** | Details of how Unity transforms scripted data structures and object states into a serialized format for storage or reconstruction later on, and how this affects application performance. |

## Additional resources

* [Script compilation](/engine/6000.7/manual/programming-environment/script-compilation.md)
* [ScriptableObject data assets](/engine/6000.7/manual/scripting/get-started/fundamental-unity-types/class-scriptable-object.md)
* [Text-based scene files](/engine/6000.7/manual/working-with-scenes/text-scene-format.md)