Focus throw is the amount you rotate a lens’s focus ring to move focus through its range, usually measured from the lens’s closest focusing distance to infinity.

A longer focus throw means you turn the ring farther for the same change in focus distance. That gives finer control, which is helpful for precise manual focusing because small ring movements produce smaller focus changes.

Many manual-focus lenses have a longer focus throw for exactly that reason: accuracy and smoother fine adjustment. Autofocus lenses often use a shorter focus throw so the lens can move through the focus range more quickly, helping autofocus acquire focus faster.