A shader variant collection is effectively a list of shader variants. Use shader variant collections to prewarm shader variants, or to ensure that shader variants that are required at runtime but not referenced in a scene are not stripped from your build.
You can create a shader variant collection asset in the following ways:
When you select a shader variant collection asset in your project, you can view and edit it in the Inspector.
You can also configure a shader variant collection asset using the ShaderVariantCollection API.
To avoid visible stalls at performance-intensive times, Unity can ask the graphics driver to create GPU representations of shader variants before they are first needed. This is called prewarming. For more information on prewarming the shader variants in a shader variant collection, see Shader loading: Prewarming shader variants.