What are the different types of stem cells and where do they come from?

There are two types of stem cells, embryonic and adult stem cells with their own pros and cons. 

 

Embryonic stem cells are derived from embryos that were fertilized in the lab with the consent of both donors, not deriving from a woman's body like many people believe. Embryonic stem cells are commonly successful in cell cultures, or growing cells under controlled conditions. Embryonic stem cells are capable of become any cell type but it is unknown if it would cause immune rejection. We do not fully understand the capabilities of stem cells due to the fact it was just recently approved by the FDA. 

 

Adult stem cells are difficult to find in mature tissues and growing them in cell cultures has proven to be a struggle. Adult stem cells though, and thought to less likely be rejected due to the fact that you can take the stem cells from the patient and be reintroduced decreasing the chances of immune system rejection. (2)