A sturdy metal or lightweight frame, depending on the model.
A needle mechanism that moves up and down to create stitches.
A presser foot that holds fabric securely while sewing.
Adjustable stitch length and width, with many models offering straight, zigzag, and decorative stitches.
A bobbin system that supplies the lower thread.
A handwheel and foot pedal (or treadle on antique models) to control sewing speed.
A built-in thread tension adjustment for even stitching.