iTunes gives you the option to either back up to computer or back up to iCloud. What are the differences and benefits to either or?
Backing up to to the computer
For backing up to to the computer, one benefit is that you don't need an internet connection to access the back up. Back-up is done automatically when you have selected the 'Back up to computer' option and you are connected to the PC/Mac. This means that whenever you back up to the computer your personal files (i.e. your photos, apps, songs, etc.) on your iPhone at the time are saved. If you have a lot of files, this could mean you are taking up a lot of space on your hard drive.You can delete your files on your iPhone or Apple product and restore it using your last backup.
Backing up to iCloud
For backing up to iCloud, you are essentially saving your content to Apple's servers. This is handy because you don't have to worry about losing your backup if your Mac or PC fails. But, you do have to have Wi-Fi to connect to Apple's servers. iCloud is convenient if you have multiple apple products. It allows you to sync across the products including but not limited to the iPhone and iPad. There is an option to manually sync to the iCloud or alternatively if you are plugged into an outlet, connected to Wi-Fi, and your phone is locked, it will sync once per 24 hours. There is no archive of the personal files you have. For example, should you delete a photo and then sync with iCloud. There will be no trace of the photo in iCloud.
You can also do both. This means backing up to both the iCloud and your computer simply by changing your selection in iTunes.
Conclusion: If you have multiple Apple products, I would go with iCloud. I've opted to just back up to the computer, because I find it unlikely that I will lose my computer and only have an iPhone to sync with.