Liquid crystals (LCs), are substances that exhibit long-range order in one or two dimensions, but not all three. Liquid crystals are substances that exhibit a phase of matter that has properties between those of a conventional liquid, and those of a solid crystal. Liquid crystals are ordered in one or two dimensions only. Liquid crystals all exhibit some degree of fluidity. The formation of liquid crystals is a direct consequence of molecular asymmetry. It arises because two molecules cannot occupy the same space at the same time and are largely entropically derived. As research into this field continues and as new applications are developed, liquid crystals will play an important role in modern technology. Crystalline materials demonstrate long-range periodic order in three dimensions.