A bobbin is a small but important part of a sewing machine. It holds the lower thread that works together with the top thread to create stitches. When you sew, the needle carries the top thread down, and the bobbin thread loops with it to lock the stitch in place. Without the bobbin, your sewing machine can't form proper stitches. Most bobbins are placed in a bobbin case under the nee... https://sewingwire.com/what-does-a-bobbin-do-on-a-sewing-machine/