# EntityTypeHandle

> A handle to the Entity component type, used to access an ArchetypeChunk 's entities in a job.

## Definition

* **Type:** Struct
* **Namespace:** [Unity.Entities](/engine/7000.0/script-reference/unity/entities.md)
* **Assembly:** UnityEngine.EntitiesModule

```csharp
public struct EntityTypeHandle
```

## Remarks

Passing a type handle to a job automatically registers the job as a reader or writer of that type, which allows the DOTS safety system to detect potential race conditions between concurrent jobs which access the same component type.

To create a EntityTypeHandle, use [ComponentSystemBase.GetEntityTypeHandle()](/engine/7000.0/script-reference/unity/entities/componentsystembase/getentitytypehandle.md). While type handles can be created just in time before they're used, it is more efficient to create them once during system creation, cache them in a private field on the system, and incrementally update them with [EntityTypeHandle.Update](/engine/7000.0/script-reference/unity/entities/entitytypehandle/update.md) just before use.

## Methods

| Method                                                                                            | Description                                                                                                                                                                                                                       |
| ------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [ToFixedString](/engine/7000.0/script-reference/unity/entities/entitytypehandle/tofixedstring.md) | Returns "EntityTypeHandle".                                                                                                                                                                                                       |
| [Update](/engine/7000.0/script-reference/unity/entities/entitytypehandle/update.md)               | When a EntityTypeHandle is cached by a system across multiple system updates, calling this function inside the system's OnUpdate() method performs the minimal incremental updates necessary to make the type handle safe to use. |