Overcast is a sewing technique that involves creating small up and down
stitches in order to tightly join two material pieces together. This approach gives resilience and prevents the material from fraying. The sew together may be used for a selection of stitching projects, such as sewing the hem, stitching appliques, or even making blankets. It offers a tidy and professional look for the final item.
whipstitch WordReferencecom Dictionary of English