Buttonhole stitch is a type of hand embroidery stitch used primarily to create a finished edge on fabric. It is commonly employed in sewing to reinforce buttonholes, preventing fraying and providing a neat appearance. The stitch is made by looping thread around the edge of the fabric, forming a series of small, evenly spaced stitches. This stitch can also be used for decorative purposes, adding texture and detail to various projects. It is versatile and can be adapted for different fabrics and designs, making it a popular choice among both beginners and experienced sewers.