Halos are glowing areas around light sources. Use them to give the impression of small dust particles in the air, and add atmosphere to your scene.
Note: This workflow is compatible only with the Built-in Render Pipelne. For similar functionality in other render pipelines, see Lens flares and halos.
Add a Halo component to a GameObject with a Light component. Then set its size and color properties to give the desired glowing effect.
Note: A Light can also display a halo without a separate Halo component by enabling its Draw Halo property, but you cannot configure its size and color.
To see Halos in the scene view, check Fx button in the Scene View Toolbar.
To override the shader used for Halos, open the Graphics window and set Light Halo to the shader that you would like to use as the override.