What are plants doing? What are plants all about? They...

What are plants doing? What are plants all about? They serve human beings by being decorative, but what is it from its own point of view? It's using up air; it's using up energy. It's really not doing anything except being ornamental. And yet here's this whole vegetable world, cactus plants, trees, roses, tulips, and edible vegetables, like cabbages, celery, lettuce - they're all doing this dance.