The difference is the use of the contraction "won't" versus "will not." Although "won't" is a contraction of "will not," it doesn't lend the same amount of weight to the word "not." Therefore, if you want to emphasize the "not" aspect of the sentence, you should use "will not." "Won't" works just fine to convey the same meaning, but does not emphasize the "not" element of the sentence. In other words, both constructions mean the same thing, but they each have a different emphasis. "Won't" is more colloquial and thus less likely to be used in writing. I hope this helps.

Alas, it is much easier and quicker for you to read, than for me to explain! http://www.educationbug.org/a/won---t-and-will-not.html BTW: reading this gave me the answer to another question someone else had asked! So you see, we are all learning from each other! Anyway, I hope this helps!

Sorry I meant the first one.

Exactly the same, except that the second can save you some energy.