Entity concepts
An entity represents something discrete in your program that has its own set of data, such as a character, visual effect, UI element, or even something abstract like a network transaction. An entity is similar to an unmanaged lightweight GameObject, which represents specific elements of your program. However, an entity acts as an ID which associates individual unique components together, rather than containing any code or serving as a container for its associated components.
Collections of entities are stored in a World, where a world's EntityManager manages all the entities in the world. EntityManager contains methods that you can use to create, destroy, and modify the entities within that world. These include the following common methods:
| Method | Description |
|---|---|
CreateEntity |
Creates a new entity. |
Instantiate |
Copies an existing entity and creates a new entity from that copy. |
DestroyEntity |
Destroys an existing entity. |
AddComponent |
Adds a component to an existing entity. |
RemoveComponent |
Removes a component from an existing entity. |
GetComponent |
Retrieves the value of an entity's component. |
SetComponent |
Overwrites the value of an entity's component. |
Note
When you create or destroy an entity, this is a structural change, which impacts the performance of your application. For more information, see the documentation on Structural changes
An entity doesn't have a type, but you can categorize entities by the types of components associated with them. The EntityManager keeps track of the unique combinations of components on existing entities. These unique combinations are called archetypes. For more information about how archetypes work, see the documentation on Archetypes concepts.
Entities in the Editor
In the Editor, the following icon represents an Entity: 
. You’ll see this when you use the specific Entities windows and Inspectors.