Cell differentiation is the process by which a less specialized cell becomes a more specialized cell type. This occurs during the development of an organism, where stem cells, which can become any cell type, gradually transform into specific cells like muscle, nerve, or blood cells. Each specialized cell has unique functions and characteristics that enable it to perform its role in the body. During differentiation, cells undergo changes in gene expression, which means certain genes are turned on or off. This process is crucial for the formation of tissues and organs, allowing for the complex structure and function of living organisms. Factors such as environmental signals, growth factors, and cell-to-cell interactions play significant roles in guiding differentiation.