Stem cells are a special kind of cells due to their ability to duplicate and differentiate in different kinds of cells.
there are different kinds of stem cells. The main diference betwen them is the kind of cells they can differentiate into.
for example, when an embrioyo is develoment, the firs cell that is form after the coito is a totipotent stem cell, because it has the ability to diferenciate in every kind of cell in the body. Afer a few weeks, in bovines it would be aroun 8 days, the cells become pluripotent, because they can generate every cell in the body, but the placent. and when we become adults this cells are know as mesechymal (multipotent), that are cells that can diferenciate in certain kind of tissue