What does Top Stitch mean?
A simple stitch that is straight and very common.
Heddels explains Top Stitch
Topstitching is a sewing stitch usually used for hems, seams, and necklines to give a garment a more finished appearance.
Both functional and decorative, it is sewn on the right side of the garment and helps to keep layers in place and edges lying flat.
Topstiching on a pair of Cheap Monday denim: