Cell differentiation is the process by which cells become structurally and functionally specialized, allowing the formation of distinct cell types (e.g in the nervous system: different types of neurons and glial cells).

The structural and functional specificity of a cell depends on the proteins it synthesizes. Recently, emerging evidence has shown the importance of noncoding RNA regulation in multiple developmental processes, including cell differentiation. 

With very few exceptions, all cells of a given organism contain the same genetic information (genomic equivalence). Differentiated cells are genetically identical but express different genes. Thus the process of differentiation involves the control and maintenance of differential gene expression.