What is the ultimate rule???
There is three basis rules making sure you have everything backed up. To lower the risk of loss data, you should have three copies of the files and things you don’t want to loss: the original copy (that flies that you have on your computer already), a backup of that original, and a backup of the backup (so that you will have two). It’s ideal to not that the both backups stored in the same place. You can keep one with you in the event that you will have to restore and recover, and you would keep the other one in a safe place where it’s not in physical threat (so that it can’t be stolen or doesn’t get wet). Keeping a backup of your backup is just a minimum, you can keep extra copies too if you choose, it wouldn’t hurt anything.
A great example of the three backups (option two) are: the original data is already stored on your PC or laptop, the first backup that you have created would be on the external hard drive or flash drive, whichever, that you would have disconnected and put in a safe place when you are not using it, then the last copy would be safely kept on an online storage service.
The most common method is option one, which assumes the service that you chose to use online is backing up properly and storing your data in several different places. It should give you your three copies, but for the sake of this we will say that the third copy is on your computer and the online service is maintaining it.
