Difference between schotty defect and frenkel defect

In frenkel defect density remains same because there is only movement of cations and anions inside the crystal. Whereas, in Schottky defect density is decreased because cations and anions are missing from the crystal. Moreover, frenkel defect is shown when there is a large difference between cations and anions while in Schottky defect anions and cations are of similar size.