Why was the battle of Coral sea important?

Answer 1

It was important because it made the Japanese weaker since they were going to sent the troops from Coral Sea to New Guinea, and they had call off their attack on New Guinea to protect the rest of Japan.
It was history's first clash of carrier fleets. It taught navies how to conduct naval battles with aircraft carriers; it also taught navies how to fight in the sky against opposing aircraft over the oceans.
It was one of the turning points for Pacific War. It contributed a significant amount of losses to the Japanese Navy and Air forces, while proving American Metal.
It was history's first sea battle between aircraft carrier fleets.

Answer 2

First clash of carriers. It taught naval airmen how to fight aerial battles at sea. The following month came Midway, where they could put their newly discovered skills into operation.
There are several paragraphs explaining the importance of the Battle of the Coral Sea in the link listed below.