If you are an iPhone aficionado like me, you probably know that there are 2 different ways to backup your device: iTunes and iCloud. But what is the difference between the two? And do you know when to use one method above the other? Let me sort this all out for you.
First of all, to be able to backup on iTunes you need a computer with the iTunes software installed (free download it here: http://apple.co/2q0yJBM). This method will save a copy of your phone on iTunes, so basically directly onto your computer. Backing up your iPhone on iTunes is much quicker than backing up on iCloud (normally under 5 minutes), it is reliable and can be used for backing up in all cases except these three: 1) you have no computer, 2) your computer isn't reliable or 3) your phone started showing signs of software failure, in which cases you will need to use iCloud for your backup.
If your iPhone is glitchy or started acting up, it is essential that you use the cloud instead of iTunes for backing it up. Why? Simple: while iTunes makes an entire copy of your device including the bugs and glitches, iCloud will only save the information of your data which will be restored completely, minus the glitches and other potential OS issues.
For your iCloud backup to be successful, you need a stable WiFi connection and a couple of free hours in front of you to let your iPhone back up completely without being interrupted. I cannot stress this enough: do not leave the WiFi area until the backup is complete, otherwise you would need to start over. You might want to do it at night with your phone plugged in to the charger to avoid a disconnection.
If you've got iCloud automatic backup turned on, it's possible that your free 5GB of storage is full so you'll either need to purchase more space or delete some old backups laying around in your cloud space. Personally, I'd rather pay $1,29 for 50GB/mo and avoid the headache, but that's just me.
In a nutshell, backing up to iTunes is a great option for almost all situations, it is reliable, fast and free. On the other hand, backing up to iCloud requires a little bit more preparation and patience, and maybe a couple of dollars, however it is necessary in some cases especially if you are here because your iPhone is acting up and you just found out that its software is corrupted. You can fully trust iCloud for a bug-free backup while iTunes might just copy your exact same issue and you'd find yourself having to start this whole process all over again (and I don't want that for you).