Hi Ryan,
When you get your certification, you have a certain number of hours in what they call a "closed" environment. This is usually a local pool. During these sessions, you get to practice all the skill you need to master in order to get your certification. They do this so you can practice in a controlled envirionment before they put you out in the ocean to try things out.
All the skills you learn in the pool, you will have to do when you do your ocean dives. Basically, this is to show that you can keep you wits about you in an open water environment and not forget to focus.
It can sound a bit overwhelming, but if you listen to your instructor and ask questions if you don't understand or if you need help, you will be just fine. Don't be afraid to ask. I always try to keep in mind that if I am wondering about something, there is bound to be at least one other person in the group who is wondering about the same thing and is just to afraid to ask. Everyone can learn from the questions other ask. So ASK, ASK, ASK!
=)
Cheers,
