How do we learn about corals?

            By trying to answer questions, such as:

What are they?
How do they look like?
Where do they live?
How are they distributed on our globe?
What do they feed on?
How do they reproduce?
How are we, humans, troubling them?
Are they affected by storms and other natural calamities?
What are their uses to humans as well as to other animals and plants?
What is their role in evolution?
(and much more)