Organic cofactor is called coenzyme and inorganic cofactor is called simple cofactor eg. Metal ions. prosthetic group can be organic eg. Heme group. Inorganic elements are metal ions eg. Zn2+
Cofactors are loosely bound nonprotein part of holoenzyme. prosthetic groups are tightly bound cofactors and do not dissociate during activity eg. Heme, flavin, biotin etc.