Imagine, you may use several devices for your personal purposes. The list of the devices can be the following:
- personal computer (desktop or laptop)
- smart phone
- tablet computer
- smart tv
So, you have stored data on many devices. You need to decide, which data is important for you, which data loss would hurt you.
All my important data is stored on my laptop. For example, if I want to read some document on my smart phone, I simple make a copy of the document from my laptop to my smart phone. But your case can be a little different. You may are creating something important using your smart phone and that means, that than you need to backup also you smart phone.
Summary for me: I actively use a laptop and a smart phone. But I do not create any important data for me using my smart phone. All my work is being done on my laptop.
I have a very important directory on my laptop. I use this directory for storing all my important data- documents, books, audios, videos, pictures, binary files for example. I own several external hard disks. I created an sh script using the Linux program rsync to mirror my laptop directory to the external harddisks. Every day I finish my work I take one of my external harddisks and launch the backup.
I have the rule: all the important data goes to that one directory. If there would be a failure of my laptop, I have all important files backed up. If such a disaster happened one day, I would buy a new laptop and used all the data from the backups.
I think, the data are often more important than a computer.
You can buy a new computer, when the old one breaks. But nobody can return you all the important data you may not have a backup for.