For longevity: make multiple copies. Harddrives: fill them up with photos and leave them stored at your parents' place. Cloud: back up to at least 1 cloud pro

For longevity: make multiple copies. Harddrives: fill them up with photos and leave them stored at your parents' place. Cloud: back up to at least 1 cloud provider (Dropbox, Amazon, ...). Local: local computer, of course. That's 3 backups there, which is not a bad start. Next: burn some DVDs etc. and again, leave copies at your parents' house. For photos, my final backup (additional to the above) are printed photo books of which I make multiple copies and hand out as presents to mother-in-law etc. More copies in more formats = longer life. Think about how your kids are going to recover these.