Here's a breakdown of what this means:

* Self-renewal: Stem cells can divide and create more stem cells, maintaining their population. This is like having a never-ending source of these versatile cells.

* Differentiation: Stem cells can transform into different types of cells, such as muscle cells, nerve cells, blood cells, or skin cells. This allows them to repair damaged tissues and organs, and even potentially create new ones.

This unique combination of self-renewal and differentiation is what makes stem cells so powerful and promising for medical research and treatment.