Ink and linear tools: pen, brush, marker, highlighter, and the line family.
Draw tools leave an open stroke. Nothing here encloses an area or carries a fill, which is what separates them from Shapes: a Draw stroke has two ends, and a shape has none.
The group splits in two. The ink tools follow the pointer freehand, and differ only in how the stroke is shaped and how large it can get. The linear tools take clicked points and draw exact geometry between them.
Every ink stroke is smoothed as it is committed, and the larger the tool the more smoothing it gets: the wobble that shows in a one-point pen line is invisible under a twenty-point highlighter, so there is no reason to preserve it.