Entities
Entities represent the building blocks of your game or app. For example, you might have an Entity which displays your player character as a sprite on-screen. You could create many entities which each represent environment objects, effects, enemies, or on-screen UI text.
Entities in DOTS Mode can only exist as part of an Entity Scene.
Creating Entities
There are a number of ways to create Entities in the Editor. When you create an Entity it becomes part of an Scene in the Hierarchy.
The Create button in the Hierarchy window
The context menu allows you to create a new Entity, either in the root of the currently active Scene's Hierarchy, or as a child of the currently selected Entity. This menu also allows you to create a new Entity Scene.
Creating a new Entity in the Hierarchy window
Creating Entities by dragging Assets from the Project window:
You can also create a new Sprite Entity by dragging a Sprite Asset from your Project window into the Scene window. Unity will create a new Entity in the currently active Scene, set up with the correct components to display the Sprite that you dragged.