Maybe because its a class of things, you can't visualise 'furniture', but you can visualise instance such as an office chair, or dinning table. My description

Maybe because its a class of things, you can't visualise 'furniture', but you can visualise instance such as an office chair, or dinning table. My description is poor, office chair is also a class, but it not the top class ... I dunno read about this once anyway, didn't make it up, honest!