@ThatMikeGuy A brief description: there are two groups of curve drawing tools
How to use these is up to the users, some are present in other illustration apps also so they may be familiar.
group 1: these are more commonly used
Pen - this is the regular pen tool
Pencil - similar to other apps, painting curves
Path Sketch - this is VectorStyler specific, similar to Pencil but can intersect+union the curves as you draw
Brush - these are real vector brushes (that is, the content of the brush is also vector)
Line - well, a simple line tool
group 2: these are a bit more complicated, some of these are present in other apps also.
these can be of two type: parametric (retains editability), or just directly creating cubic Beziers
The first 3 are creating regular paths with lines and curves:
Curvature tool: creates a bezier shape with smooth curvature (similar to Illustrator)
Bezigon tool: (similar to Freehand) lines and beziers (press Option/Alt for beziers)
Arc tool: curves drawn as arcs
The next 4 create parametric (live) shapes interpolating a sequence of points with various methods:
Interpolated Shape: cubic interpolation, you can select the interpolation method in the Shape panel (or in the top row)
B-Spline - interpolating B-Spline over a sequence of points, set the degree of interpolation in the panel
Spline - cubic interpolating splines
Curvature Shape - same as the Curvature tool, but retains the line shape and you can set the curvature precision in the Shape panel