“Sit-down long arm”
 

What is a sit-down long arm? I have a Tiara . What is that categorized as?

Sit down is where you move the fabric, and there are no feed dogs.

Sometimes they call them mid-arms, but the function is the same. Likely called mid-arm because the throat depth is on the lesser side, usually 16-18 inches.

This is in contrast to a "standard" longarm where you move the machine, not the fabric.

Tiara is a sit-down. Long arm, mid arm, same thing. The "sit down" implies the "move the fabric" vs "move the machine".