Arm positions used everywhere: ballet classes, ballet performances. It's a base for all ballet movements; even other dance styles as jazz, modern and so on use all arms positions in choreography.
Preparation Position
Make an oval with arms while keeping them down. Your arms should be parallel to your body, between your thighs and your arms should be a gap as a size of your palm. Your palms should be turned up.
First position
Arms should make an oval, and your palms and elbows should be on the same level as your belly button. Your palms should be turned towards your belly. Keep shoulders down and back should be straight.
Second position
Arms open to the side. Arms should be a little bended. Try to keep your elbow up, but the same time your palms should look forward (turned to the front). Shoulders should be kept down all the time.
Third position
Bring your arms up and make an oval. Turn your palms toward yourself. While keeping your head straight, you should able to see your palms if you look up only with your eyes. Elbows should be looking to the sides. Shoulders are down.