Factory reset a macbook pro?

i know i use the disks i got with it. but which one? one is called 13-inch Macbook Pro (applications install DVD) and 13-inch macbook pro (Mac OS X install DVD) both say Dvd..so i tried booting with the 2nd one, and all my stuff was still there. it took about 30 minutes to complete sooo idk what it did but it didnt factory reset it.