Regular Battle Position
This battle position/formation is the regular battle formation. Your Final Fantasy VII Party on one side, and the baddies on the opposite side. This position has no effecting changes to your ATB Time Meter and your battle experience is regular.

Pre-Emptive Position
In this position your party starts of early, meaning your ATB Time Meter is started Full. Your enemies are in their prospective, a Back Attack. Meaning, they have their positions not faced towards your party, meaning this position is a full-advantage to your party.

Back Attack Position
This could be said to be the entire opposite of the Pre-Emptive Position. Your party starts out with an empty ATB Time Meter, meaning that the disadvantage is to you. Your party faces the enemy backsided.

Side Attack Position
Your party is surrounded by both sides, and your ATB Time Meter is started at zero, and your enemies have the advantage of course.