Genomic imprinting is a genetic phenomenon where certain genes are expressed in a parent-of-origin-specific manner. This means that for some genes, only the allele inherited from one parent is active, while the allele from the other parent is silenced. This selective expression can influence various traits and developmental processes in an organism. Imprinting occurs through chemical modifications, such as DNA methylation, that affect gene activity without changing the underlying DNA sequence. It plays a crucial role in growth and development, and disruptions in imprinting can lead to disorders like Prader-Willi syndrome and Angelman syndrome, which are caused by abnormalities in imprinted genes.