Beginning with a previous vectorial result about the synodic solar rotation dependence on the inclination of solar equator the classical definition of synodic solar rotation has been reconsidered in some detail. The angular difference between one synodic and sidereal solar rotation turn, $\Delta \lambda$ as a function of the longitude of the Earth and the inclination of the solar equator, $\beta$, indicates a substantially different nature of trigonometric and vectorial definition of synodid solar rotation. Only a long-term mean value of $\Delta \lambda$ does not depend on $\beta$. For the extreem case, $\beta = 90^\circ$, $\Delta \lambda$ shoes a purely geometrical discontinuity. On contrary, the siderial, apparent annual and synodic rotations of the solar globe are smooth and can be described by the corresponding vectorial angular velocities.