FAQS - DATA BACKUP, SYNC, ARCHIVE
THEY ARE ALL THE SAME THING, RIGHT?
No. Sync or Syncing data means you have identical sets of data stored in 2 or more locations/devices/data storage this can be a manual or mostly an automatic process - your contacts on your phone if setup correctly will be synced to your online account with say Apple or Samsung or Google. This can be done by Wi-Fi or mobile data.
A backup of data is a copy of your current data, taken and stored on another device or another location or cloud storage area. This can be done manually, or done automatically, on a schedule - hourly, daily, weekly, monthly, etc. It can also have available the history over time.
Archiving is to take data, normally not currently used, and storing it somewhere else, another drive, an online archive, in a draw on a hard drive. It can also be used to take a yearly snapshop of your data.
WHICH TYPE TO I NEED?
Most people use Syncing of data in their everyday lives, email, Dropbox, iCloud, Google Drive (File Stream) and are ok. They may also use a bit of backup of data - Moving WhatsApp to a new device or just making sure you don't lose all your chats - you should be backing up that data. If you have Apple Time Machine - you are backing up data.
If you have an external hard drive, and on it you put lots of old folders with data from years ago, old CV's, etc, then you put that in a draw. That's archiving. Or you might copy data up to a cloud storage area but don't have that on your computer/device - that's archiving if you don't access it much, or backup if you keep it up to date regularly, or data sharing if others can access and they make updates or changes.
Short answer - you should be using all other them, but it depends upon what data, and how important it is. Only Backups and Archiving will protect you from Ransomware, but synced data might not.