Stem cell biology is the study of stem cells, which are unique cells capable of developing into various cell types in the body. They have the ability to self-renew, meaning they can divide and produce more stem cells, or differentiate into specialized cells, such as muscle cells or nerve cells. This versatility makes them essential for growth, development, and tissue repair. There are two main types of stem cells: embryonic stem cells, which are derived from early-stage embryos, and adult stem cells, found in various tissues throughout the body. Researchers explore stem cell biology to understand how these cells function and to develop potential therapies for diseases like cancer and Parkinson's disease.