Ghost 14 backup file structure

Am new to using Ghost 14.  Just changed from Ghost2003.  Can't get my head round th structure of the backup directories and files.  Looked in the book and it really isnlt clear about "sets" etc.  I seem to have files going back to October although I have set up, I think, for a new set monthly and to keep 2 sets.

 

In the file backup I have over 70 folders named fbfFiles_*** where *** is 54C or somesuch.  In each of these folders are various numbers of files named ***.fbf where fbf is a string of letters/numbers a few of which tie up with the  last three characters of the folder name.

 

In the drive backup I have files with extensions of .v2i, .iv2i and sv2i.

 

Which does what?  Which are linked together? Is there a straight forward piece of paper that will make sense of this to someone who is still stuck with .gho and .ghs!!!