A beginning student asked me recently, "What's the difference between 'pas de bourree' and 'balance'?" We had learned both steps within the space of a couple of weeks and she was confused, seeing as how both steps seemed to have 3 parts and involved shifting the weight from one foot to the other.
The question stopped me short. I knew I knew the difference and could show it to her but articulating it was another matter. First of all, let's look at the definitions:
Pas de bourree: It consists of three quick steps. It literally means 'Step of the Drunken Lady' and when done à la seconde the feet usually change positions (right left right or back, side, front). (Wikipedia)
Balance: A rocking step. A step that shifts body weight from one foot to the other, usually in 3/4 time. A balance may be performed by crossing the foot in front or in back. (About.com)
Btw, balance is often called a waltz step because it is done in 3/4 waltz time, da-dum-dum, da-dum-dum.
Now, here is the practical difference: with pas de bourree, we start with the weight on one foot and end on the other but with balance, we simply shift to one foot and then back. Try it yourself:
For pas de bourree, start with your feet in fifth position, right foot in front. Lift the left foot to coupe, step onto it, step side with the right foot and then step forward with the left. Your weight shifts from right to the left, to the right and to the left - back, side, front.
For balance, start with your feet in fifth position, right foot in front. Degage the right foot to the side, step onto it, bring the left foot to coupe behind the right and rock onto the ball of the foot and then settle back down onto the right foot. You've just done right, left, right.
And there you have it. Happy dancing!