when Itunes in my pc backs up my iphone, where can I find the file that contains my texts, applications, notes? I can find my music but not all the other content.

I have backed up my iphone to Itunes in my pc but neither itunes nor my pc tells me where the file is located. I can see my music in itunes but the texts, applications on iphone, notes, photos, where can I find them on my pc to be sure they are backed up? I will be changing iphones soon and want to be sure all my data in iphone is saved. Thank you.