Finishing stitches are used to securely end a piece of thread by anchoring it to the fabric.
Also see Holding stitch for how to use this method to finish your thread.
Flat Holding Construction Appliqué Ayrshire Basic Bead Embroidery Crewelwork Cutwork Goldwork Hardanger Mountmellick Opus Anglicanum Silk shading Stumpwork Surface Wessex Stitchery Whitework
Working in an area that will subsequently be hidden beneath stitching, make two tiny stitches. Alternatively (if this is the last stitching in this area), carefully angle your needle and bring it up between previous stitches and make two tiny stitches, hiding them under your existing stitches.
Bring the needle through to the top of the fabric and cut it off close to the fabric surface.
Structure of stitch
Various Authors, The Royal School of Needlework Book of Embroidery (2018) , p.39