Stem cell research involves two main types of stem cells - embryonic stem cells found in embryos and induced pluripotent stem cells created by reprogramming adult cells. The document outlines key researchers in the field including Leroy Stevens who discovered stem cells and Shinya Yamanaka who discovered induced pluripotent stem cells. It discusses the pros and cons of each type of stem cell and potential applications to treat diseases like Alzheimer's, heart disease, and diabetes. The document concludes by recommending increased focus on induced pluripotent stem cells to avoid ethical debates and pushing for more funding and research efforts going forward.