No, those are straight lines.
@th straight lines are curves too, with the right parameters.
also, will forever stan de Casteljau
@th having been there¹ I can confirm that those segments are an approximation of what in real life *are* curves (and they aren't flat in the z direction either!).
¹ we needed a place to stop for a night more or less in that area. it was chosen for very reasoned reason such as the name
"B-splines oughta be good enough for anybody."
—Apple, circa 1991