Significance of reference field in a DFF

What is the significance of reference field in a DFF?

Using reference field in the DFF, you can toggle the DFF on the basis of reference field value. But using a field as a reference field has no effect on the field itself. That is, the reference field is simply a normal form field that has nothing to do with the flexfield unless you define the flexfield to use it as a reference field. If we use a reference field, the value of that field will populate its own column.