Segment Information when Generating EDFs

It's fine, I'm not asking the right question. Here's a screenshot:


My question is, how do you determine how to split up the EEG into these segments? You notice how there are seven segments? Are you receiving these instructions from the EEG file? I also use Nicolet's software which generates 7 edf files when I export the exact EEG. So i'm starting to believe the EEG file is instructing the software how to segment it. Am I wrong? Since both Brainstorm and Nicolet produced 7 Edfs for the same EEG file, that must mean they both operate the same way? That's why I'm trying to understand how Brainstorm segments the EEG file. I want to modify the original EEG file so that when I import it into brainstorm it'll be one segment not seven. So I need to learn how Brainstorm is making this decision.