Backing-up is a process by which data is copied from one location to another for storage purposes. This stored data can then only be changed if the user opens the storage location and actively changes or deletes that data. Backing up should never be confused with syncing. Backing up and syncing your data, what's the difference?
The primary means by which you should back up your .nebo files is by exporting them to an external location for safekeeping, such as your device’s hard drive or a memory stick.
For more information, please visit: Back up your notes
It is always advisable that you regularly back up your .nebo files to protect yourself from data loss just in case the unexpected ever happens.