The quantized Hall effect occurs in two-dimensional electron systems subjected to low temperatures and strong magnetic fields. In this phenomenon, the electrical resistance becomes quantized, meaning it takes on specific discrete values rather than a continuous range. This effect is observed in materials like graphene and semiconductor heterostructures. This quantization leads to the formation of Landau levels, which are energy levels that electrons occupy in a magnetic field. The Hall conductance, a measure of how well a material conducts electricity in the presence of a magnetic field, is quantized in units of e²/h, where e is the elementary charge and h is Planck's constant.