How to backup my iPhone before updating the version?

How do I backup the files I have on my iPhone before I update my iOS version? I want to do it because I want to unjailbreak my iPhone. It's so stupid because you can't update you iOS version without unjailbreaking it. I decided to unjailbreak it and never jailbreak it again.

Using Itunes

You can back up some things in iTunes but mail, contacts, calendars etc do not back up in iTunes.

You can back everything up in the cloud and pull it back once your phone is reset.

  • Will updating my iPhone apps affect my phone speed as how updating the Operating System (OS) will? Currently I'm using the iPhone 5s on iOS 8.3 I know if I were to update my phone to the latest OS I may notice some slowdown on my phone's performance, since it may not have the "muscle" to handle certain functions. Many apps now are optimised for iOS 9 and/or the 6th generation phones. Will my 5s' speed performance slow down if I update my apps? Will the app's performance slow down?
  • What will happen if i don't backup my Iphone files after updating my Iphone? So i had an iphone 4 and i tried updating it to IOS 5.1 and after updating it told me to backup my files so i backed up and it is taking forever to back up it has been like an hour the bar did not even move it moved a little from the start. Can i chose not to backup will anything happen if i don't back up? I currently used 29.1 gb space in my iphone I only have one place to store my stuff 382 GB of 451 GB used
  • Updating jailbreaked iPhone 3gs to latest version? I have jailbreaked my iPhone 3g(or 3gs; tell me any method by which i can check that even) and currently it is on 4.2.1. I want to upgrade it to latest ios version i can update it to so that i can install apps which require latest IOS version. Also i want it to be jailbreaked even further i have upgraded it.
  • Updating iOS version on iPhone itself? Hi, I was wondering if I updated my iPhone to the latest version, on the iPhone itself; i.e, not going through iTunes, but rather by settings>update, will I lose my photos, contacts! And will I lose my jailbreak!