What is the difference between the Blind Hem Foot and regular stitching?

The Blind Hem Foot allows you to professionally finish projects with a machine hem that is undetectable from the right side. You set the machine for Blind Hem Stitch, finish the hem edge, fold and press it, then position it under the foot so the fold is against the center guide. The widest zigzag stitch catches only 1 or 2 threads of the fabric fold, creating an invisible hem. (Page 11)