I hope all is well. Lets see what we can do to help sort this out for you.
SOFS is actually an active/active role that runs on a cluster. The cluster has shared storage between the cluster nodes. Disks are provisioned on the shared storage, made available to each cluster node, added to the cluster, and converted into CSVs. Shares are then created on the CSV and are made active/active on each cluster node via the active/active SOFS cluster role.
Cluster Shared Volumes (CSV) enable multiple nodes in a failover cluster to simultaneously have read-write access to the same LUN (disk) that is provisioned as an NTFS volume. (In Windows Server 2012 R2, the disk can be provisioned as NTFS or Resilient File System (ReFS).)
With CSV, clustered roles can fail over quickly from one node to another node without requiring a change in drive ownership, or dismounting and remounting a volume. CSV also helps to simplify the management of a potentially large number of LUNs in a failover cluster.
CSV provide a general-purpose, clustered file system, which is layered above NTFS (or ReFS in Windows Server 2012 R2).
So effectively it is the combination of the 2 technologies that yields the best results, performance and failover protection.
Now, there are A LOT of do's & do nots associated with the decisions to deploy, and what to use for what scenarios. If you are interested in taking a deeper look, see the following:
Hope that helps to clarify a bit. Remember that for the exam, you may see scenarios around what technology/solution is BEST SUITED for the situation described, so I would take a look at the specific scenario driven discussions on the pages I suggested above.
If you have any additional questions, please let us know as needed.
Good Luck !!