Embryonic Stem Cells are able to develop into any type of Cell. (Pluripotent)

http://en.wikipedia.org/wiki/Embryonic_stem_cell

Pluripotent: Embryonic stem cells are able to develop into any type of cell, excepting those of the placenta. Only embryonic stem cells of the morula aretotipotent: able to develop into any type of cell, including those of the placenta.