What is the difference between roti tawa and dosa tawa?

I'm curious, could you explain the fundamental distinction between roti tawa and dosa tawa? I understand they're both cooking utensils, but what sets them apart in terms of their intended use, material, or even cultural significance? Are there any specific recipes or cooking techniques that are uniquely suited to one over the other? I'm eager to learn more about these two essential kitchen tools and how they contribute to the culinary landscape.