IPhone may be a bit complicated for some especially when you are a first-time user. You may need to restore your iPhone for many reasons and some of you might not be aware how to do it. First and foremost- always and ALWAYS make sure that you have a backup done already. For avoiding risks associated with losing all your data, it is always recommended to manually backup your iPhone through iTunes! If you are not aware of how to do it, read on:
Connect your iPhone to your laptop. Make sure you have iTunes downloaded already. Here is a link to download iTunes- www.apple.com/in/itunes/download/
As soon as you connect your iPhone to your laptop, you will see itunes popup. Click on the phone icon on top left and you should see all the details like music, photos, apps etc.
You will see an option like ‘Manually backup and Restore’ under ‘Backups’. Select ‘iCloud’ under that section and click ‘Backup’.
It may take few minutes to backup after which you could click ‘Restore Backup’. Your iPhone will restart and then sync with your computer. Stay connected until the sync finishes.