We all assume that we can keep information forever in our new digital world.
This is not true. Data behind information does corrupt or lose integrity over time. It can also be attacked and deleted. There are mechanisms that allow you to know when any of this has happened but when it does there is often little one can do to remedy the situation.
Multiple backup (1 close, 1 read only, 1 remote) help but that can be cumbersome and difficult to manage. Plus it is only any good if you regularly recover and check the integrity of your backups routinely.
At home I’d always recommend at the very least a cloud backup (yes, something you must pay for.) On site networked (protected) backups also help.
I’d like to say I also record everything to DVD and give it to a mate to look after – but I don’t.
With the exception of keep DVDs of everything forever all of these can still be corrupted by the most vicious malware around today, crypto-malware. These can find and encrypt your backups. Best protection? Always keep your system, antivirus and backups up to date. Possibly invest in an anti always product too.