Stem cell research holds promise for new medical treatments but also raises ethical issues. There are several types of stem cells with varying differentiation potential. Embryonic stem cells can become any cell type but their extraction requires embryo destruction, raising moral concerns for some. Adult stem cells are more limited in differentiation but do not require embryo destruction. Religious views vary between support and opposition to embryonic research. Overall, the document discusses stem cell biology and properties, sources of stem cells, the potential medical applications and ethical issues surrounding stem cell research.