A more complex transfer occurs when the orbits are not coplanar, in that case there is an additional delta-v necessary to change the plane of the orbit, the velocity of the vehicle needs a substantial change and the delta-v is usually high.
A more complex transfer occurs. The velocity of the vehicle needs a substantial change. The velocity of the vehicle needs the delta. The orbits are not coplanar. There is an additional delta-v necessary to change the plane of the orbit in coplanar. V is usually high.