Cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type, allowing for the development of diverse tissues and organs in multicellular organisms. During differentiation, cells undergo changes in gene expression, leading to specific functions and characteristics. This process is crucial for development, growth, and repair in organisms. Stem cells, which are undifferentiated, have the potential to develop into various cell types, making them vital in research and medical applications, including regenerative medicine and tissue engineering.