Everything you need to know about updating your iPhone

Make sure that your device is compatible with the update

First of all, you should check whether your device is compatible with new updates. Because not all iPhone models get along with software changes, Apple excludes them from getting new operating system updates. The best way to find out if your iPhone works with a specific version of iOS is by checking on the official website of Apple. Otherwise, you can Google something like Your iPhone model +compatible with +iOS version to get the list of iOS versions supporting your phone. For example, the recently released iOS version, iOS 13, supports the following iPhones:
iPhone 11 Pro Max, iPhone 11 Pro, iPhone 11, iPhone XS Max, iPhone XS, iPhone XR, iPhone X, iPhone 8 Plus, iPhone 8, iPhone 7 Plus, iPhone 7, iPhone 6s Plus, iPhone 6s, iPhone SE
if you don't have one of these devices, sorry, you won't be able to upgrade to iOS 13. Instead, you need to consider upgrading to the lasts iOS supporting your iPhone.

Prepare your phone for the update

Before you supercharge your iPhone with an update, you should get your phone ready to digest that.
It is very important to backup your phone before any upgrade. You never know what could go wrong during the update, and having a good backup lets you restore your phone to the recent condition if the update fails. You can either use the iCloud-the traditional method- to make a backup of your iPhone or plug it directly to your PC or laptop and back it up via iTunes. You can also do both. Having two backups is always better than one, isn't that right?
Clean out storage on your device. iOS upgrade requires a certain amount of free space on your device. If your iPhone has run out of space, the system will show you a message and stop upgrading. As an alternative solution, you can upgrade your phone using a computer, but it is not the best solution. So, it is advised to clean unnecessary content on your phone before heading for a major update. Delete redundant photos or music or move them into iCloud or a third-party service like Google Drive.
Purge unused Apps. Perhaps there are some apps on your device that are unused for a while or you don't know what they are for. Just go to Settings > General > iPhone Storage and uninstalled apps older than one year.
Delete your Beta profile. Odds are good that you are currently running a beta version of iOS. Installing the official version means downgrading. While t is possible but it could be challenging. So, it is better to delete your beta profile before going back to the official version.

How to update your iPhone manually?

1- Plug your iPhone into power and connect to the Internet via Wi-Fi (it is advised that you change your phone battery at least to 50% before update starts)
2- Navigate to Go to Settings > General, then choose Software Update.
3- Tap Download and Install. If you have not enough space on your device the installer asks you to let it temporary uninstall apps. It will reinstall apps after the upgrade is complete. Tap Continue or Cancel.
4- If you want to upgrade now tap install, otherwise you can choose Install Tonight or Remind Me Later. If you selected to install updates at night, don't forget to plug your iPhone into power before you go to sleep.
5- If asked, enter your passcode.

How to install updated automatically?

With iOS 12+ you can configure your device to get updates automatically. go to Settings > General > Software Update and turn on Automatic Update. Your iPhone will be updated to the latest iOS whenever available. However, some updates might require manual installation.
To enjoy the latest features and make your phone faster and more stable you need to regularly update your phone's iOS to the recent official release. Happy Upgrading!