What's the difference between B2 vs Backblaze Online Backup?

Online Backup:

Backblaze Online Backup backs up PC and Mac desktop computers with "unlimited backup" for a flat fee, for all the data attached to a computer, including external USB hard drives. The personal backup product is encrypted and data in the backup is only accessible by the account owner. You can find information about personal backup pricing here. 

The online backup service includes software to automatically manage the backups of a Mac or Windows computer. The Backblaze Online Backup software creates a mirror copy of the data on the licensed computer, except for data explicitly excluded, with a running 30-day file revision history.

Backblaze has introduced extended version history that, for an additional fee, will keep your data for up to 1-year or permanently.  Information on how to set this up is here.

Backblaze Online Backup is not designed to be used as offsite data archival or offsite storage for data that will not be retained on the licensed computer. 

Read more about Personal Backup here: https://www.backblaze.com/cloud-backup.html

B2 Cloud Storage:

B2 is generic cloud storage. You can use it from any computer, on any operating system, for any cloud storage purpose.

Service charges for B2 are variable based on the amount of data storage, bandwidth used, and transactions performed. For more information about B2 pricing please see here.

Data stored in B2 is not encrypted, making it possible to share files with other people or serve up data for websites, downloads, or applications. However, we do offer the option to apply Server-Side Encryption to buckets. You can find out more about our Server-Side Encryption and how it works in our Server Side Encryption FAQ and Enabling Server Side Encryption guide.

B2 does not include any client software to interface with the storage. The storage is accessible via web GUI, API (with which third party software can integrate with, such as these: https://www.backblaze.com/b2/docs/integrations.html), or Command Line Tool (https://www.backblaze.com/b2/docs/quick_command_line.html)

As data in B2 is not tied to a specific computer, data archival or offsite data storage are both excellent use cases for B2. 

Read more about B2 Cloud Storage here: https://www.backblaze.com/b2/cloud-storage.html

For information on how Business and Personal Backup differ please view the following article:

Personal Backup Vs Backblaze for Business