Stem cells are the specialized cells that are obtained from different organs and have the ability to grow into a new organ. They are of various types:
Embryonic stem cells - They are isolated from the early embryo of the humans and are kept in the laboratory conditions, they show the property of pluripotency and thus have the ability to make a completely new organ.
Non-embryonic or adult cells - They are present in children as well as adults, they can be obtained from various types of tissues that can be brain, skin, bone marrow, muscles etc. E.g.; In the transplant of blood or bone marrow stem cells, hematopoietic cells are utilized.
Induced pluripotent stem cells - These are the stem cells are artificially induced into pluripotent stem cells and they are capable of forming a completely new organ.
Amniotic fluid or cord blood stem cells - These are stem cells that are isolated from the umbilical cord or from the amniotic fluid (fluid around embryo) and are preserved, they can later be used in the treatment of several diseases like Leukemia etc.