A question about how to use it

"Delete threat" deletes the file the threat was found in.  "Clean up threat" attempts to remove the malicious code from the file the threat was found in.  On a Mac, these are almost always identical, as we don't have many file infectors.

For example, if you have a Word document that is infected with a macro virus, Clean Up will leave you with a usable Word document but no macro virus.  Delete will delete the file.

I guess deleting is always safest, but you might actually want to keep the file that is infected in some cases -- hence the clean up option.

thank you Andrew!

I just posted this very same question (will go delete the post now!).  

I suspected it might mean "delete the actual file", but that seemed pretty dramatic, so I wanted to be sure.

However, the "Action" that SAV suggested to me (for "clean up manually" style threats) was to choose Delete threat  for the custom scans of the infected files.  It never warned me that this meant deleting the actual file -- i assumed it was simply going to delete the infection within the file.  Luckily they were just Java cache files (I don't even know what that means, other than that they aren't that important).  There should be a warning to avoid accidental dumping important files, especially since there exists an option of de-contaminating them without destruction.  Now that I know this, I can better understand why SAV suggests not fiddling with the default of "deny access" (allowing the user to deal with the infections however they see fit, via the Quarantine Manager). i.e. Initially, I thought "why on earth wouldn't you simply just to choose delete said viruses asap?!?"