A computer backup is a copy of your data that you store on a separate device. This includes documents, family photos, contacts, videos, emails, apps, etc. If the originals are located on your laptop or mobile device, you keep the backup somewhere else that's safe - this way, you can use the second copy to restore your files or system if something happens to the original.
You need to back up your computer so that you can restore it if something happens. You can use software like Acronis Cyber Protect Home Office to automatically back up all the changes you make to your computer, including files that are hidden and might be missed if you copied them manually. This makes the process of restoring your computer much easier and faster.