Hydrogen has the potential to decarbonize the energy and industrial sector in the future, mainly if it is generated by water electrolysis. Proton Exchange Membrane water electrolysis (PEMWE) system is regarded as a propitious technology to produce green hydrogen from water using power supplied by renewable energy sources. It offers many benefits such as high performance, high proton conductibility, quick response, compact size, and low working temperature. Many conceptual and functional parameters influence the effectiveness of PEM, including temperature, pressure of anode and cathode regions, water content and wideness of layer, and cathode and anode exchange current density. In addition, the anodic half reaction (known as oxygen evolution reaction (OER)), and cathodic half reaction (known as the hydrogen evolution reaction (HER)) perform an important function in the development of PEMWE. The current paper aims at presenting these parameters and discussing their impacts on the performance of PEM. Also, the PEM efficiency is presented. The different methods used to enhance the scattering of OER electrocatalyst and minimizing catalyst loading to minimize the price of PEMWE are also highlighted. Moreover, the alternative of noble metals that could be used as electrocatalyst in HER and OER to minimize the cost of PEM are reviewed and presented.