In the past 10 years, industries and research institutes have given fuel cells a lot of attention as a unique means of generating electrical energy. A better choice is required to store and utilize green energy in the future compared to traditional fossil fuel, which has limited reserves and notorious pollution problems. Fuel cells (FCs) remain pieces of instrument that transform a fuel’s chemical energy, such as hydrogen, alcohols, or hydrocarbons, into electrical energy and heat via electrochemistry. Numerous benefits, including their lower emissions, higher efficiency, and lesser maintenance requirements, have sparked a great deal of attention in this practice in recent years. The basic parts of fuel cells are described, along with the material concerns that are associated with them. A thorough review of the fundamentals of FCs technology is given in this chapter, with particular attention paid to the two most common forms of FCs: solid oxide and polymer electrolyte membrane FCs. This chapter discusses the state of the art of these technologies, their prospective applications, and the challenges they may encounter in the future.