I have searched everywhere and cannot figure out what this is and how it is used? What do you write in it?
There is no “personal bio,” per se. The applicant provides some basic personal information when they set up their account, and then answers some questions regarding their family. Of course, there is also the main “personal statement,” or essay, but that’s not typically written as a bio (though it usually draws on some personal experience).
I don’t think the personal bio is required. If something is entered there, it is added to the student’s resume. See this video, which doesn’t even address the personal bio, but you can see the student entered a one sentence statement: For Students: Scoir Student Overview [Video] - User Guide and Support Documentation | Scoir
The bigger question is why is your student doing the coalition app? There are no schools that are uniquely on coalition app anymore. So, best to use the common app and/or college’s own apps.