The Microbial Fuel Cell (MFC) is a bioreactor with which the chemical energy in chemical bonds of organic compounds are converted to electricity under anaerobic conditions through catalytic reactions of micro-organisms. It has been familiar for a long time that electricity can be generated directly through using bacteria to break organic matter. A microbial fuel cell can also serve in different wastewater treatment to destroy organic matter. The development of MFC technology requires a greater understanding of the microbial processes for MFCs, and their components, limitations, factors and design this system, to be simpler and large scale system developed; so that it would increase electricity production while being cost-effective. This review discusses, what is the MFCs and the basic principle of how MFC operate, the most essential MFC components and their relevance, multiple MFC designs that have been presented as efficient configurations, Applications of MFCs, and several types of wastewater as substrates in MFC also highlighted.