The 2 main types of stem cells are embryonic stem cells and adult stem cells. This video discusses on both of them. It also tells you how adult tissue differentation is linked with embryonic development and how each layer differentiates into different organs. Timeline: 0:00 Stem Cells 1:38 Embryonic Stem Cells 3:08 Adult Stem Cells 7:38 Adult tissue differentiation and regeneration - Embryonic Development 8:10 Growth Factors