Use these options to set what happens when you select Create > EP Curve Tool.
The higher the Curve Degree, the smoother the curve. The default setting (3 Cubic) works well for most curves.
The knot spacing specifies how Maya assigns U positioning values to knots. Chord length knot spacing distributes curvature better. If you use the resulting curve to build a surface, the surface might display texture mapping better.
Uniform knot spacing produces curve U positioning values that are easier for you to predict.