The document discusses different types of sewing machines. It describes lockstitch sewing machines which can be foot or electric powered and are used domestically. It also mentions hi-speed lockstitch sewing machines which are straight stitch machines or industrial machines. An over edging machine finishes raw edges while an embroidery machine makes fancy stitches. A button holer machine makes buttonholes, a button attachment machine attaches buttons, and a double needle machine is used for inseams. A bartacking machine reinforces pocket openings.