From what I understand these are
Crochet and fabric quilts.
Patchwork is joined together using your choice style of crochet that is what the blanket stitch on each block is used for. The squares are like completed mini quilts with the seams already done. The ones I saw had backing and batting along with your top fabric and had been turned and sewn around then blanket stitches with yarn or crochet yarn to be joined. Some can have some pretty fancy joining.