Kokopuffs, when you add alcohol (ie. wine, bourbon, etc) and deglaze a pan you still add flavor to the liquid that you then add next. So deglazing is a way of adding flavor to a liquid, it also helps to pull up all those caramelized bits stuck to the bottom of the pan, helping them to also flavor the liquid and to keep them from burning.
As for flambeeing, as Nicko pointed out, only part of the alcohol gets burned off. Liquids will only flambe when their alcohol content reaches a certain point. As the alcohol burns it becomes more diluted until it gets to a point where the alcohol content can't support a flame
As an example, the bourbon sauce that I make: I caramelize veg in a pan. I then deglaze with bourbon and flame it to burn off the alcohol, leaving just the rich caramel and oak tones to the bourbon. I then add my demi and seasonings. Reduce that, add cream, reduce again. Then, just before straining I add a bit of raw bourbon to give the sauce just a hint of that raw alcohol bite.