In recent years, stem cell therapy has become a very promising and complex scientific research topic. In the body, stem cells have the capacity to differentiate into a wide variety of cell types. They are capable to regenerate body system. Adult stem cells and embryonic stem cells are the two primary categories of stem cells. Through cell- replacement therapies, stem cell-based therapies can give the opportunity to replace lost, damaged, or old cells in order to regenerate or repair tissues and organs. Additionally, using genetically altered stem cells as delivery systems holds enormous potential for treating inherited genetic flaws and delivering therapeutic chemicals to specifically injured tissues and organs. The ensuing integration of science and medicine made possible by more research will enable the therapeutic application of ES cell technology. In the end, such a program might present a remarkable new weapon in the fight against human sickness.