Reiterated genes are those that are repeated in the genome multiple times. Some common synonyms for reiterated genes include "tandem repeats," "gene amplification," "gene redundancy," and "multigene families." Tandem repeats refers to a sequence of nucleotides that is repeated one after the other, while gene amplification refers to the process by which a gene is duplicated in the genome. Gene redundancy describes multiple genes within a genome that perform the same or similar functions. Meanwhile, multigene families are groups of closely related genes that have evolved from a common ancestor and may have similar functions but also exhibit some differences in gene expression or regulation. Regardless of the term used, reiterated genes are essential for genome evolution, development, and function.