Overcast represents a sewing technique which involves creating small in and out stitches to securely connect two material pieces together.
This method gives resilience and avoids the material from fraying. The backstitch may be used for a selection of stitching projects, such as hemming, sewing patches, or even making blankets. It provides a tidy and professional look for the completed product.
Whipstitch Definition Meaning MerriamWebster