If you don't have 2-3 copies of your data, your files are not safe. Backing up is a must with all our digital media and other files these days. Making a local copy to an external drive is a good first step. However getting another copy offsite gives you peace of mind.
Backblaze is a good online (cloud) solution for this. Works on both Macs & PCs. Encrypts and uploads all your files to secure datacenters. Restore from the web, get DVD(s) or USB drive sent via FedEx. Best of all, it's unlimited storage for per computer for $5 Per month.