Burning Questions: Salted vs. Unsalted Butter

• I just made a batch of chocolate chip cookies and the recipe called for unsalted butter. What is the difference between using unsalted butter versus regular butter (besides the salt, obviously!) ?
• I LOVE BUTTER 
• Actually, the difference is just the salt! When you use unsalted butter, you have more control over the amount of salt that goes into the recipe.  Some people care about this for dietary reasons; others for taste.  Different types of salted butter have different amounts of salt in them, so some may make your recipe taste different while others wouldn't change the taste that much.  Also, if you are cooking a recipe that calls for yeast, remember that salt controls the yeast activity (and too much salt will just kill it), so if there is butter involved there, definitely use unsalted so that you know how much you are getting!  No one likes dead yeast ;-( 

Hope that helps!