Blank or custom form path

Blank/Custom: it's the same but not

For your first form, the middle pane will be blank. But after that, all the forms your space uses will be listed here.

You can create a blank form, you'll have to add fields to it.

Edit previously used forms. This assumes you aren't change much to it.

Use selected form, treats it like a template with the expectation you will make changes

Delete the selected form,