In Unity, a gizmo is a visual aid rendered in Unity's Scene View to help us in the development process. Several components in Unity use gizmos to tell the developers where in the 3D world these are located.
Take a look at the following screenshot. The two icons, the movie camera and the light bulb, are gizmos that indicate the game object position of the camera and the point light components, respectively.
You can do the same with a specific game object if you click on the cube icon in their inspector pane:
Here you have three options to choose:
Use a label
Use a built-in icon
Use a custom icon made with any image located inside your project
You will see the following three results, respectively, in the Scene View:
Any of these gizmos will be attached to the game object and will persist in the scene and in any prefab containing this game object.
All these examples use the Unity editor to do the required setup, but there is an additional way in which gizmos can be created, allowing greater...