ShaderLab: grouping commands with the Category block

Use the Category block to group commands that set the render state, so that you can “inherit” the grouped renderingThe process of drawing graphics to the screen (or to a render texture). By default, the main camera in Unity renders its view to the screen. More info
See in Glossary state within the block.

For example, your ShaderA program that runs on the GPU. More info
See in Glossary object might have multiple SubShaders, each of which requires blending set to additive. You can use the Category block for that:

Shader "example" {
Category {
    Blend One One
    SubShader {
        // ...
    }
    SubShader {
        // ...
    }
    // ...
}
}

The Category block does not have an impact on shader performance; it is essentially the same as copy-pasting the code.