Longarm Quilting refers to using a large sewing machine to finish a quilt. Sewing the three layers of a quilt—backing, batting, and top—together is regarded as the quilting step.

Longarm refers to a sewing machine that has a throat space larger than 15 inches. The larger machine is generally on a frame and moves along the frame to baste or finish a quilt. Longarm Quilting can be computerized or hand-guided.  A longarm sewing machine can also be fixed to a table, and that is generally referred to as a stationary machine.

For comparison:

Midarm refers to the size of the throat space of the machine. The throat space of a midarm quilting machines can range from 9 to 15 inches and can be stationary or be on a frame.

Shortarm refers to the size of the throat space of the sewing machine less than 9 inches. Shortarm machines are often domestic home-sewing machines that serve many other functions than finishing quilts.