这些备份选项意味着什么?

I am currently trying to backup an empty SQL Server 2008 R2 database that I designed for a project that is getting shelved for the time being. I was going through the back up procedure through the SQL Management Studio when I noticed there was an option to make a Copy Only Back Up. I looked it up to see what it was but I didn't fully understand the options I was getting. I am currently trying to backup an empty SQL Se