Backups are probably one of the most boring topics in computers. That is, until you lose a file, a disk drive, or a whole computer. Then they become the most important thing in the world. There are a couple of approaches to backups.
The easiest is simply copying your important files to a disk. Or to something equivalent, like magnetic tape or other external storage. This is normally the first method that people turn try. However, there are a few things to consider about this method. Firstly, how many disks do you use? Using only one disk means you risk losing it. Extra disks mean extra cost. Secondly, where do you store the disk? If it’s in your house or office, one disaster wipes out all your data. Thirdly, how do you secure the disk? A normal disk can be read by anyone. If you encrypt it, the keys need to be backed up.
The disadvantage of this method is that it is manual. While some parts can be automated, disks (or tapes) need to be carried around and plugged in. And when your method is manual, you risk it not getting done. Still, it is a perfectly serviceable method, as long as you manage the processes well.
Nowadays with the ubiquity of the Internet, there is an alternative. Backing up to the “cloud”. For most people, this is AWS or Azure or Google. Or more simply, a service like Dropbox or Google Drive. But it could be backing up to an off-site computer that you own. In many ways, the methods are similar whether you use your own or another’s computer. But most of the time, it is simply easier to set up an account on a cloud provider and go from there. While uploading can be done manually, it is incredibly easy to automate. And indeed, there are a number of people who package backup as a service. Still, a simple script on an automatic schedule may be all you need.
So, you or your business will need to have backups. The method you choose will depend on a trade-off between risk and cost. And in making that choice you will need to consider reliability, redundancy and security.