Stem cell differentiation is the process by which unspecialized stem cells develop into specialized cell types with distinct functions. This process is crucial for growth, development, and tissue repair in organisms. Stem cells can be categorized into two main types: embryonic stem cells, which can become any cell type, and adult stem cells, which are more limited in their differentiation potential. During differentiation, stem cells respond to various signals from their environment, such as chemical cues and physical interactions. These signals activate specific genes that guide the stem cells to transform into particular cell types, such as muscle cells, nerve cells, or blood cells. This ability to differentiate is essential for maintaining healthy tissues and organs.