The player in our game is an ECS entity, with the PlayerData component attached to it:
As you can see in the previous fragment of code, ECS components are plain structs implementing the IComponentData interface. This interface lives in the Unity.Entities namespace. Note how we are putting all of our code inside the CCG namespace. This is a good practice to prevent name clashes when using third-party code.
The PlayerData struct stores two integers:
As we will see during the course, the ECS is all about structs and value types rather than classes and reference types. This is one of the main reasons behind its "performance by default" motto.