There are different types of stem cell, typically broken into four types:

• Embryonic stem cells - Stem cells taken from human embryos
• Fetal stem cells- Stem cells taken from aborted fetal tissue
• Umbilical stem cells - Stem cells take from umbilical cords
• Adult stem cells - Stem cells taken from adult tissue

For medical purposes the most useful stem cells occur at the early stages of life. These early stage stem cells have the wonderful ability to develop into any of the 300 types of cell found in all of us.