You certainly don’t want a system crash to destroy your most important documents and photos. Maintain redundant backups of your data across many different media types. Consider cloud-based backup as well as external HDDs or thumb drives or even newer solid state drives (SSD).
The 3-2-1 rule is a good general framework for backing up your data:
- You should have at least 3 total copies of your data backed up
- Ensure 2 of them are local but are on different media (e.g., external hard drives, solid state drives or SD cards)
- Keep 1 offsite, likely in a online-based backup service