In most places, the Vermilion Bird, White Tiger, Azure Dragon, and Black Tortoise are called by the names Suzaku, Byakko, Seiryu, and Genbu. They're traditionally associated with the four elements of fire, air, water, and earth, and also with the cardinal directions of south, west, east, and north respectively.

[That's the easiest and most succinct explanation she can give.]

It's like that for everyone when they first get here. But the good thing is everyone is in this together, and you should be able to rely on the other Heroes to help you out in a pinch. Which Jobs do you have equipped? I might be able to explain how some of them work.