CustomEditor Inherits from System.Attribute

Tells an Editor class which run-time type it's an editor for.

Note: This is an editor class. To use it you have to place your script in Assets/Editor inside your project folder. Editor classes are in the UnityEditor namespace so for C# scripts you need to add "using UnityEditor;" at the beginning of the script.

When you make a custom editor for a component, you need put this attribute on the editor class.