In SOLIDWORKS, any sketch entity can be specified for construction. Points and centerlines are always construction entities only.
Use a centerline as the axis about which a sketch revolves to create a base feature, or to mirror sketch entities.
SOLIDWORKS also has Reference Geometry (planes, axes, and coordinate systems) as a basis for creating features outside of sketches.
Use planes to construct a series of sketches as the basis for a loft feature.
