There are several reasons such as uncompromised security, premium quality; attractive design and more why I prefer Apple devices. Whether it's Mac, iPhone, iPad, or Apple Watch, each one of them stands out of the rest, doesn't it?
Managing more than one Apple devices is quite simple. Most people, including me, use a single Apple ID in order to manage their devices with a bit ease. Moreover, there are some handy benefits of keeping all Apple devices signed in with the same iCloud account. As for instance, it allows you to automatically sync your data across all the devices, auto-download apps etc.
It's important to remove the device from Apple ID after you have sold it out, given away to someone or lost it. Fortunately, Apple makes it quite easy to not only check which device has been signed into your Apple ID but also allows you to remove it.
Check Which Devices Have Been Signed Into your Apple ID
Step #1. First off, you have to sign in to your Apple ID account page.
Step #2. Then, scroll to Devices. (In case you don't see your devices, click View Details and answer your security questions.)
Step #3. Next up, you need to click any device name in order to view its information like the device model, serial number, and OS version. This information may vary from device to device.
How to Remove an iPhone or iPad from Apple ID
If you no longer use any device, you can remove it from the list.
Step #4. Follow the first three steps mentioned above. While viewing the information of any Apple device, click on Remove.
Step #5. Check out the message that appears. Click again on Remove to confirm.
Following are a few things to keep in mind
Your Apple device might reappear on your account next time it connects to the internet if you are still signed with your Apple ID.
You will have to remove the device from your account page, sign out of iCloud, iTunes, iMessage, FaceTime, and Game Center, or erase the device (Settings → General → Reset → Erase All Content and Settings) to remove it permanently.
If you have enabled two-step authentication for your Apple ID, verification codes will no longer appear. At the same time, it won't have access to iCloud as well as other Apple services such as, Find My iPhone until you sign in again with two-factor authentication.