Ubuntu :: Bash Scripting - To Copy A List Of Files

I'm writing a bash script to copy a list of files and do some stuff to them. Basically, I have the code written that does what it needs to do, but I can't quite understand why it works. I was hoping someone could clear up my understanding a bit.

Code:

The first line generates a list of files. I wrap each line in quotes because they usually have spaces in the directory names.

The second line changes IFS, and I understand what IFS itself does. What I don't quite get is what the separator becomes with that echo statement. If I'm reading that correctly, the backspace will remove the newline and essentially the result is nothing? I found this solution on a web page somewhere, but it was years old and there was no real explanation.